Aerospace Engineering Research Projects

This project is sponsored by the Department of Education Graduate Assistance in Areas of National Need (GAANN) fellowship program to support six to 10 Ph.D. students of high ability and financial need in the Department of Aerospace Engineering at Embry-Riddle Aeronautical University. The purpose of the program is to enhance and diversify the pool of U.S. citizens who are qualified to teach and pursue research careers in the field of aerospace engineering.

Embry-Riddle's Aerospace Engineering Department is among the top aerospace engineering programs in the nation. It is currently ranked 32nd for its graduate programs and 8th for its undergraduate program by U.S. News and World Report. The department currently has 34 faculty comprised of distinguished researchers and teachers in the fields of aerodynamics and propulsion, dynamics and control, as well as structures and materials.

GAANN Fellows will participate in a formal training/teaching program, which will allow them to learn, observe experienced teachers and gain hands-on experience in teaching. Fellows will receive instruction on effective teaching techniques and will be evaluated formally on their teaching. A far-reaching recruitment plan will allow Embry-Riddle to identify outstanding and eligible students, especially from traditionally underrepresented groups. Embry-Riddle is contributing matching funds in the form of tuition and fee assistance. 

If you are interested in being supported as a GAANN Fellow, please contact Dr. Lyrintzis at lyrintzi@erau.edu.

Research Dates

09/01/2018 to 09/30/2024

Researchers

Tasos Lyrintzis
Aerospace Engineering Department
Ph.D., M.S., Cornell University

Marwan Al-Haik
Aerospace Engineering Department

William Engblom
Aerospace Engineering Department
Ph.D., M.S., The University of Texas at Austin

Troy Henderson
Aerospace Engineering Department
Ph.D., M.S., Texas A&M University

Gordon Leishman
Aerospace Engineering Department
Ph.D., Eng.Sc.D., University of Glasgow

PI: Ebenezer Gnanamanickam

Dates: 9/2022 – 9/2025

Funding:  U.S. Army

This work focuses on understanding the coupled interactions between large and heavy solid particles, on a particle bed, and a gaseous (air) carrier phase turbulent boundary layer developing over the bed. Here, large refers to particles with diameter greater than the dissipation scale and heavy refers to particles with density much larger than the carrier phase. This work will lead to a deeper understanding (and subsequently better predictive models) of particle-carrier phase interactions impacting a variety of fields from the geophysical sciences to traditional branches of engineering. Studying their coupled interaction requires synchronous measurements of both the carrier and particle phase dynamics at high spatial and temporal resolution. To tackle this challenge, the proposed work will use advanced optical diagnostic techniques to study these interactions, thus providing new insight into their physics. The proposed work is broadly divided into two parts.

Part I – The incipient mobilization of particles by the carrier phase is currently predicted by various measures of the mean shear of the carrier phase velocity field. However, there is increasing evidence that particle mobilization is an inherently unsteady process better correlated with the unsteady carrier phase eddies. The proposed work seeks to systematically quantify and understand these unsteady aspects of particle mobilization, particularly as a function of the energy and scale size of the carrier phase eddies. The proposed approach is to introduce flow scales of controlled energy and scale size into a turbulent boundary layer developing over a particle bed, while methodically characterizing the subsequent initiation of particle mobilization. The properties of the particles, namely the diameter and density, will be varied. As the carrier phase is fixed (air), the proposed approach will then describe the processes of particle mobilization as a function of not only the carrier phase eddy energy and size but also the particle Reynolds and Stokes numbers.

Part II – Once particles are mobilized, they form a saltating layer adjacent to the particle bed and become two-way coupled with the carrier phase flow. This interaction, thus far has been reported as modifications to the carrier phase turbulence statistics. However, the exact nature of this interaction has yet to be studied in any further detail. Specifically, the scale dependence or the energy transfer mechanism of this coupled interaction has yet to be described. To study this interaction, it is proposed to carry out careful measurements of the carrier phase turbulent boundary layer in the presence of a saltation layer.

In addition, during the course of both parts of the proposed work, detailed, simultaneous measurements of both phases will be carried out, in a time-resolved manner, to describe the scale dependent characteristics of the underlying physics. This will involve establishing an instantaneous shear velocity that initiates particle mobilization as a function of particle properties as well as carrier phase eddy scale and energy. While studying the interactions during mobilization and after a saltating layer is formed, the goal will be to establish scale dependent energy transfer pathways between the carrier and particle phases. To this end, the primary measurement technique used to characterize the carrier phase will be particle image velocimetry (PIV), while the particle phase velocity fields will be measured using particle tracking velocimetry (PTV). These PIV/PTV measurements will use multiple cameras at multi-scale, providing a detailed description of both phases of the flow at high spatial and temporal resolution. Together these techniques will then provide unique multi-scale, multi-phase measurement sets that will capture the detailed interactions of the particle and carrier phase, leading to new insights into the physics of these interactions.

PI:  Ebenezer Gnanamanickam

Dates: 7/2022 – 6/2025

Funding:  National Science Foundation (NSF)

This research focuses on understanding the interactions between turbulent flows and long (high aspect ratio), flexible hair-like microstructures or micropillars inspired by those encountered in nature. Some examples include lateral line sensors in fish, airflow sensors in bats and hair cover of animals such as seals and bats. These structures perform several physiological functions such as balance and equilibrium sensors, flow sensors, flight control sensors, thermal regulators and water harvesters. Particularly, hair-cell sensors have such structures which in conjunction with the animal's nervous system forms a mechanoreceptive device i.e., they turn a force or displacement, in response to the flow energy, into a nervous system response. These structures that vibrate in response to the background flow are also important in energy harvesting systems. However, these interactions are poorly understood primarily due to the complexity of the underlying physics. Capturing this physics requires simultaneous, combined measurements of the micropillar motion and the flow velocities which are challenging. The proposed research will use advanced image-based flow diagnostic tools to measure in detail the interactions between arrays of these micropillars and the background flow. The planned outreach activities will target a group that is almost exclusively comprised of students who are under-represented in the sciences, while also being economically disadvantaged. The graduate student supported will be involved in outreach activities, inculcating a spirit of outreach into the next generation of engineers.

The interactions between wall turbulence and these micropillars occur in the following manner. Flow structures of scales spanning several orders of magnitude, present within wall turbulence, excites the response of the micropillars. The deflection or vibratory response of the micropillars will then feedback and modify the non-linear, background turbulence, resulting in a non-linearly coupled system. In addition, this interaction occurring at the wall can affect the entire layer resulting in a multiscale interacting layer. Of particular interest are energy transfer pathways between the micropillars and the background turbulence. To describe this coupled interaction and the associated energy transfer mechanisms, advanced diagnostic tools such as multi-camera, multi-resolution, mosaicing particle image velocimetry will be used to capture the dynamics of the background flow while simultaneously tracking the motion of relevant micropillars using particle tracking techniques. Together these tools will provide unique multiscale measurements that will elucidate the coupled physics, advancing fields ranging from physiology to aerospace engineering to non-linear energy systems.

PI: J. Gordon Leishman

Co-PI: Ebenezer Gnanamanickam

PhD Students:   Kaijus Palm and Guillermo Mazzilli

Dates: 1/2022 – 12/2026

Funding:  NASA and Office of Naval Research (ONR)

Ship airwakes are the unsteady turbulent flows that are generated by the earths atmospheric boundary layer (the wind colloquially) blowing over a ship. These flow fields are highly turbulent, not easy to predict and couple with a similar wake flow field generated by a rotorcraft operating close the the ship. This coupling as expected is extremely difficult to predict let along faithfully simulate in a flight simulator. This coupling can have catastrophic consequences for the operation or rotorcraft operating in the vicinity of Naval ships.

While ship airwakes have now been studied for several decades, there remain many unanswered questions and associated challenges in understanding these unsteady, three-dimensional flows, particularly concerning their turbulence characteristics and how flow scales in the airwake can potentially couple with those of a rotorcraft, including Unoccupied Aerial Systems (UAS). Navy personnel and aircraft safety remain the primary motivating factor for understanding the airwake and the interactions so produced. In this regard, developing a versatile, high-fidelity mathematical model to represent the ship airwake in a flight simulation, such as using a reduced-order mathematical representation, remains a priority for the technical community. This goal is particularly critical for more contemporary ship shapes typical of the current Navy inventory. It is toward this end that the fluid dynamic studies of the airwake are addressed in this proposed task. Furthermore, a vast majority of ship airwake measurements have not considered the interactions between an operating rotor(craft) and the airwake, another challenge the proposed task will address.

Overall, the mean flow features of the ship airwake are currently reasonably well characterized, at least for simplified ship superstructures such as the SFS2. However, much of the combined spatio-temporal behavior of the ship airwake, in general, has not been measured and so the physics are still poorly understood, particularly for contemporary Navy ship shapes. Organized turbulence structures, their distribution of energy across different scales, and their interactions with, or influence on, or criticality for, a traditional rotorcraft or less conventional UAS are not understood or sufficiently documented so far. The recent time-resolved airwake measurements of the current PIs have better established the true three-dimensional nature of the ship airwake, along with other turbulent aspects of the flow that have not been previously documented. These features include the high degree of intermittency, the bistable nature of the airwake, etc. These recent measurements have highlighted the predominance of low frequencies in the airwake, but not exclusively so. They indicate the likelihood of coupling with the response of any rotor system, large or small These new measurements have emphasized the need for spatially and temporally resolved high-frequency flow measurements that capture the true three-dimensionality of the airwake flow and its turbulent aspects, including intermittency. In addition, parsing these measurements into low-order mathematical models (such as for use in FlightLab or similar) remains a challenge, both in the context of understanding the flow physics and developing a higher-fidelity representation of the airwake for use in piloted simulations. Furthermore, the challenge of measuring, understanding, and representing the interactions between the airwake and a rotor system still remains to be studied at the fidelity needed if faithful models of the airwake are to be realized.

Technical Objectives (ERAU tasks only):

1) With the focus on faithfully capturing the three-dimensionality of the flow and its turbulent aspects (such as the frequency content and intermittency), time-resolved particle image velocimetry (TR-PIV) measurements with high spatio-temporal resolution will be conducted. These measurements are proposed for a more relevant ship geometry, namely the NATO Generic Destroyer (GD) of NATO AVT-315, while also investigating the differences to the widely used SFS2. Also, a representative rotor system will be introduced into the airwake to study the interactions therein. ERAU will use their new subsonic 4x6 ft wind tunnel with a mostly glass test section and the large field of view TR-PIV system awarded under an ONR DURIP. The focus will be on carrying out dual-plane, time-resolved stereo PIV (DPTR-sPIV) measurements, which allow for spatially and temporally synchronous measurements.

2) These datasets will then be used to represent the flow field using reduced-order models (ROMs). The advantages of methods such as wavelets, spectral POD (sPOD), Multi-scale Proper Orthogonal Decomposition (mPOD), and probabilistic/statistics techniques, will be used to acquire physical insights into the complex airwake environment, while describing the flow in a manner that is more relevant to the scales of UAS. This proposed approach will also offer new quantitative metrics for comparing airwakes, sorted into frequencies, which quantitatively reflect the energy distributions, and so they are much more suitable for V&V. ROMs can then be constructed, and flow field physics and interactions can be examined at each scale, whose contours should be comparable across all frequencies.

Embry-Riddle is supporting industry (i.e. Global Aerospace Corp.) in the development of a novel hypersonic wind tunnel by using high-fidelity computational fluid dynamics.

GAC is leading development of a wind tunnel in which the test article is propelled thru the test section at hypersonic speeds using a novel, proprietary approach. Due to proprietary restrictions a simplistic version of the test article is illustrated below as it moves Mach 10 from right to left. Shock waves may be observed reflecting off tunnel walls. A Phase I Air Force STTR effort has been completed and Phase II is expected to begin in the near future.

Research Dates

05/20/2021

This work carries out collaborative theoretical, experimental and numerical investigations of flow-acoustic resonant interactions in transitional airfoils which are responsible for sudden appearance of prominent acoustic tones and unsteady aerodynamic fluctuations in low-Reynolds-number airfoils.

The experimental part of the efforts is implemented in France at anechoic wind tunnel facility of Ecole Centrale de Lyon, while numerical and theoretical studies are conducted at Embry-Riddle using DOD HPC facilities. The project involves several Ph.D. and MSAE students both in U.S. and France. 

Research Dates

07/01/2013 to 10/15/2025

Researchers

Vladimir Golubev
Aerospace Engineering Department
Ph.D., M.S., University of Notre Dame

Reda R. Mankbadi
Aerospace Engineering Department
Ph.D., Brown University

This project conducts theoretical and high-fidelity numerical analyses of UAV robust flight controller employing synthetic-jet actuators (SJAs). The technology-demonstration feasibility study focuses on SJA-based suppression of gust-induced airfoil flutter.

It joins AE and Engineering Physics faculty and students (including undergraduate) in preparation for Phase 2 effort that will include experimental validation and further development and commercialization of the novel flight control technology.

Research Dates

07/01/2013 to 10/15/2025

Researchers

Vladimir Golubev
Aerospace Engineering Department
Ph.D., M.S., University of Notre Dame

This project is a collaboration with several research organizations under the supervision of FAA. The focus of the current research efforts is on developing and employing variable-fidelity prediction approaches to examine safety implications of the future integration of variable-size UAS systems in the National Aerospace System.

In particular, variable-fidelity prediction methods to accurately resolve all aspects of aircraft wake generation, evolution, interaction and control are developed. The results of this research will be incorporated in the FAA Integrated Safety Assessment Model developed for analysis of risk implications of UAS operations in the terminal zones and beyond.

Research Dates

07/01/2015 to 10/15/2025

Researchers

Vladimir Golubev
Aerospace Engineering Department
Ph.D., M.S., University of Notre Dame

The Embry-Riddle team developed a passive noise suppression technology utilizing the interactions of the airframe with the jet plume. In this technology, the flat surface of the airframe adjacent to the jet plume is modified to create a slightly wavy surface instead. Such design modification can be applied to the existing design concepts with engine mounted under the wing, as well as, the top-mounted engine configurations.

The near-field perturbations are reflected by the wavy surface to create an excitation wave to amplify the jet and the shear layer instability. The wavy-surface parameters are designed such that the excitation frequency is the harmonic of the fundamental frequency responsible for the peak noise. Through nonlinear fundamental-subharmonic interaction, the sound source and its radiated far-field noise are reduced. 

To verify this concept, high-fidelity simulations of a supersonic rectangular jet in the vicinity of the airframe surface were carried out. Results show that when the flat airframe surface is reduced by a wavy one, the radiated sound was reduced by 3.7dB for top-mounted engine, and by 2.6dB  for under-airframe engine.

Research Dates

08/18/2018 to 11/12/2023

Researchers

Reda R. Mankbadi
Aerospace Engineering Department
Ph.D., Brown University

This project is a University Turbine Systems research grant funded by the Department of Energy.  In collaboration with the University of Central Florida, Purdue University and the University of New Mexico, Embry-Riddle will develop fundamental data and modeling of H2 and NH3 fuels for gas turbine power plants.

Researchers

Scott Martin
Aerospace Engineering Department
Ph.D., M.S., University of Washington-Seattle Campus

In this project, which is funded by the FAA, Embry-Riddle and Kent University will develop training for individuals within the FAA’s Aviation Safety Flight Standards Service who have expertise and job responsibilities related to the evaluation of aircraft systems design, maintenance, operations, procedures and pilot performance.

Researchers

Scott Martin
Aerospace Engineering Department
Ph.D., M.S., University of Washington-Seattle Campus

This is an Army Sequential Phase II STTR program in collaboration with Reaction Systems Inc., University of Central Florida and Propulsion Systems Inc.  This project will develop the double conditioned Conditional Moment Closure (CMC) turbulent combustion model for afterburning shutdown of hypersonic rocket exhaust plumes.

Researchers

Scott Martin
Aerospace Engineering Department
Ph.D., M.S., University of Washington-Seattle Campus

This project investigates a novel cylinder design inspired from the Harbor Seal whisker, with the goal of reducing coolant pumping power requirements while maintaining heat transfer rates in pin-fin arrays.

Arrays of constant cross-section cylinders have been employed in many heat exchange applications. Increases in heat transfer rates characteristically result in an increase in the coolant pumping power requirements, which can be quite high for a circular cylinder array. Pin fin channels are often used at the trailing edge of the blades where they also serve an additional purpose of providing structural support. It has been found that the behavior of the flow around a wall-mounted cylinder significantly impacts the heat transfer. The boundary layer becomes broken up by the presence of the pin, creating a horseshoe vortex. This horseshoe vortex produces high wall shear stress beneath it, resulting in high heat transfer from the wall in this region. The resulting flow separation around the pin, however, results in large pressure losses. The pin fin channel has been heavily studied in the literature, in an effort to describe the heat transfer and flow behavior and improve prediction abilities. The circular cylindrical pins are relatively easy to manufacture and hence, this configuration is often found in commercial applications. However, the need to reduce pressure drop and maintain the heat transfer rates are a much needed requirement for a variety of industries to improve the cooling efficiency.

One such prominent line of research is conducted on optimizing the design of the circular cylindrical pins to increase their cooling performance. In this line of research, it was found that bio-mimicked harbor seal whisker geometry leads to the reduction in the cooling system pumping power requirements, while maintaining or improving heat transfer rates. The seal whisker geometry consists of stream-wise and span-wise undulations which reduce the size of the wake and coherent structures shed from the body as a result of an added component of stream-wise vorticity along the pin surface. Also, the vortex shedding frequency becomes less pronounced, leading to significantly reduced lateral loading on the modified cylinder. Preliminary computational studies have shown that the modified wake and vortex shedding structures resulting from the geometry tend to reduce the total pressure loss throughout the system without degrading the cooling levels.

Three different cross-section types, one elliptical, one of circular cross section and a 0.25X axially scaled type of the bio inspired pin were created for further investigation along with two baseline circular cylindrical and elliptical pins. Computational analysis for an array of the above three shapes and a standard elliptical cross-section pin array was undertaken. The results obtained were compared with the baseline circular cylindrical pin array. The main purpose of this research is to describe the heat transfer and flow characteristics of 3 novel bio inspired pin designs using steady and unsteady Reynolds-Averaged-Navier-Stokes (RANS) based simulations, in an effort to better understand their performance. These findings are important to the gas turbine community as reduced penalties associated with cooling flows directly translate to improved thermodynamic and propulsive efficiencies.

Researchers

Anish Prasad
Aerospace Engineering Department
Ph.D., M.S., Embry-Riddle Aeronautical University

Mark Ricklick
Aerospace Engineering Department
Ph.D., University of Central Florida

This project is focused on the exploration and validation of numerical modeling techniques, for the simulation of supercritical jets in cross-flow.

The injection of fuels and oxidizers into combustion chambers is often performed at near-critical or supercritical (SC) temperatures and pressures. At the critical point, the surface tension and enthalpy of vaporization of a fluid approach zero. This means there is no droplet formation in a jet, and also no density change between phases. The fluid has in effect only one supercritical phase, and has both liquid-like and gas-like properties. Physical and thermodynamic properties of the fluid have large gradients near the critical point, and this has led to complications in numerical simulation of even simple flow phenomena at this condition.

It is desired to simulate the mixing and subsequent combustion of certain supercritical fluids for application to the design of SC-CO2­ combustion power generation. SC methane and oxygen will be burned in an atmosphere of SC carbon dioxide, allowing highly efficient power extraction using smaller turbomachinery than in traditional Brayton or Rankine cycles. The study of SC methane jets also has applications to liquid rocket propellant injection and jet impingement rocket nozzle cooling.

Reynolds-Averaged Navier Stokes (RANS) and Large Eddy Simulation (LES) numerical studies are conducted to investigate the diffusion-driven mixing of one or more species in a SC jet, with another species in a SC cross-flow. Real-gas effects will be captured using the Peng-Robinson cubic equation of state. Benchmarking is performed against previous experimental and LES studies performed on near-critical and SC jets in quiescent fluids. The commercial code STAR-CCM+ is used for the simulation.

Improved prediction of jet behavior at near-critical and SC pressures and temperatures will better inform combustor design, combustion efficiency and thermodynamic efficiency.

Ideal gas axisymmetric simulation of a sub-critical nitrogen jet.

Research Dates

08/07/2016 to 08/25/2017

Researchers

Mark Ricklick
Aerospace Engineering Department
Ph.D., University of Central Florida

Neil Sullivan
Mechanical Engineering Department
Ph.D., M.S., Embry Riddle Aeronautical University

PI: Riccardo Bevilacqua
Dates: 8/1/2021-7/31/2024
Funding: Air Force Office of Scientific Research (AFOSR), $442.5K

Warhead fragmentation predictions are based on either numerical simulations or static arena tests where detonations occur in unrealistic conditions (not flying). The first methodology presents many shortcomings: there is no agreement on the state of the art for simulations, and many tools ignore important aspects such as gravity, aerodynamic forces and moments, and rigid body motion of different shape fragments. Numerical simulations are also lengthy and cannot be used as online/on-the-battlefield tools. The experimental approach is also extremely limited, as it does not reproduce the real-world conditions of a moving warhead.

The objective of this work is to combine high-fidelity numerical models with unique/ad-hoc experimental activities to strengthen basic science underpinning the test and evaluation framework for warhead fragmentation and fragments fly-out. In particular, we will aim at combining the most advanced simulation capabilities with static experimental data, to obtain a transfer function predicting lethality and collateral damage of a given warhead in real-life conditions. Artificial neural networks and/or other machine learning tools (e.g., Random Forests) will be used to capture the underlying physics governing fragments dispersion under dynamic conditions, coming from NAVAIR’s Spidy software, and eventually combine this knowledge with real warhead characteristics, coming from the static test. This proposal is of high impact because of the existing gap in analytical tools to define and validate warhead fragmentation testing.

The broader impact (long term) of this work may be a software tool that the warfighter can use on the field to rapidly assess the effects of the arsenal at his disposal. This tool will be equally beneficial to designers and testers within the Air Force and the DoD in general.

PI: Riccardo Bevilacqua
Dates: 3/1/2022-2/28/2028
Funding: Air Force Office of Scientific Research (AFOSR), $450K

The objective of this work is to create the basic science underpinning the structural testing and evaluation framework and control for deployable large spacecraft. Large space structures and those with high dimensional ratio between deployed and stowed configurations are extremely difficult to test on the ground. The AFRL’s Space Vehicle Directorate recently opened the new Deployable Structures Laboratory, or DeSeL, as evidence of a renewed interest towards these systems. DeSeL represents the state-of-the-art technology for on-the-ground experimentation of deployable systems. In particular, an active Gravity Off-Load Follower (GOLF) cart system is being currently developed, intended to have three degrees of freedom (attitude motion) which could foreseeably provide the capability for large low-frequency motions. The real capabilities of the GOLF system are yet to be determined, and this research effort will develop in parallel, assist, support and inform the development of this new facility at AFRL.

New testing and evaluation science to identify these systems’ behavior and control them, that are robust to large uncertainties in the structural dynamics are then needed, and the first time they deploy on orbit is the ultimate test.

We propose to obtain the objective by combining novel control and learning theory with ad-hoc experimental activities. The culmination of this effort will be a flight demonstration, where a CubeSat previously designed by the Advanced Autonomous Multiple Spacecraft (ADAMUS) laboratory will be modified in its design and perform autonomous on-orbit structural identification, control, and testing.

The flight demonstration will be based on measuring the natural frequencies, damping ratios and vibration mode shapes via excitation of the spacecraft, using reaction wheels on the main hub and potentially distributed small thrusters on the flexible bodies, emulating the configuration of the AFRL’s Space Solar Power Incremental Demonstrations and Research Project (SSPIDR).

PI: Riccardo Bevilacqua
Dates: 2/1/2022-1/31/2025
Funding: NASA, subcontract from UF, $150K

The following tasks will be performed by one Ph.D. student and Dr. Bevilacqua (PI at ERAU), in support of the University of Florida’s proposal for the NASA’s Instrument Incubator Program (IIP):

Year 1:

• Drag-compensation and test mass control design. Adaptive control combined with integral concurrent learning will be investigated to estimate, in real-time, the effects of drag on the spacecraft, to enable precise control of the test mass inside it. The PI has successfully used this technique for drag-based spacecraft formation flight, where online estimation of the ballistic coefficient of an unknown vehicle is critical.
• Support for drag-compensation thruster mapping. Lyapunov-based thruster selection principles, previously developed by the PI, will be used to simplify the thruster mapping problem, and prevent the use of any numerical iterations, to ease online implementation. An additional step will involve exploring the possibility to use adaptive + ICL control to also estimate the thrust errors and their misalignment.

Year 2:

• Spacecraft acceleration estimation based on S-GRS outputs. The test mass position and orientation are measured inside the sensor and the applied forces and torques on the test mass are known. How to use this information to optimally estimate the spacecraft acceleration and angular acceleration due to atmospheric drag remains a challenge. An approach based on a bank of Kalman (or Extended Kalman) Filters will be explored, possibly in iterative form, as previously done for spacecraft relative motion estimation by Dr. Gurfil at Technion and by the PI and one of his former students.

Year 3:

• Support for hardware-in-the-loop testing of the control system at UF. The PI and the PhD student will support experimentation at UF, to implement the above algorithms in hardware systems. The PI has over a decade of experience in on-the-ground testing of spacecraft GNC systems.

Year 1-3:

• Support for numerical simulation of the closed-loop system. High-fidelity orbital and attitude propagators will be used to test the algorithms developed. STK and NASA’s Spice will also be candidates for comparison.

PI: Riccardo Bevilacqua
Dates: 1/3/2022 -1/2/2023
Funding: Florida Space Grant Consortium (FSGC), $25K

The objective of this work is to start the assembly of a CubeSat hosting specialized flexible appendages, taking inspiration from a previously designed spacecraft developed by the Advanced Autonomous Multiple Spacecraft (ADAMUS). This CubeSat will eventually enable testing of ADAMUS’ developed spacecraft control algorithms on-orbit.

Relevance to NASA: The innovation proposed herein lies in the ability to autonomously characterize and control complex space structures. This project will directly support NASA’s TA 4: Robotics and Autonomous Systems

PI: Hever Moncayo
Co-PI: K. Merve Dogan
Dates: 8/2022-1/2023
Funding: SpaceWERX Phase I STTR

In this project, which is a SpaceWERX Phase I STTR program with Orbital Prime, we are developing algorithms to increase autonomy of OSAM applications. This includes the application of machine learning techniques to improve accuracy of position and orientation estimation for proximity operations in space. Machine learning include deep learning combined with vision-based navigation designed and tested in both, virtual simulation environment and actual thrust-based spacecraft system.

PI: Morad Nazari
Co-PI: K. Merve Dogan
Dates: 5/15/2022-10/15/2022
Funding: SpaceWERX Phase I STTR

Dynamic response to emergent situations is a necessity in the on-orbit servicing, assembly and manufacturing (OSAM) field because traditional on-orbit guidance and control (G&C) cannot respond efficiently and effectively to such dynamic situations (i.e., they are based on either constant mass or diagonal matrix of inertia). In these circumstances, the current challenge is to develop modeling strategies and control systems that exhibit intelligence, robustness and adaptation to the environment changes and disturbances (e.g., uncertainties, constraints and flexible dynamics). Note that the current state-of-the-art methods do not offer a reliable, accurate framework for real-time, optimal accommodation of constraints in the system dynamics that account for orbital-attitude coupling in the motion of the bodies without encountering singularity or non-uniqueness issues. In this project, the ControlX team with ERAU partnership will develop agile, reconfigurable, and resilient dynamics and G&C algorithms for on-orbit servicing to capture a broad set of OSAM applications such as remediation of resident space object (RSO) (e.g., via de-orbiting, recycle, end-of-life servicing, satellite refueling, etc.) using effective tools and methods involving geometric mechanics, constrained G&C synthesis, and reconfigurable robotic manipulators (RRMs). 

The proposed work in this Phase I includes reconfigurable systems for on-orbit servicing, assembly and manufacturing with learning control methods that minimize tracking error of the end-effector of the RRM in the presence of uncertainties, optimize configuration and accommodate constraint-changing scenarios. Our developments will avoid singularity; not rely on the concept of costates or Lagrange multipliers that are restrictive; handle system uncertainties while enforcing the constraints; use RRMs in different tasks (recycle, debris removing, maintenance, etc.); not need in sensors or exact model knowledge for robotic arms. Specifically, constrained space vehicle control (predicated on Udwadia and Kalaba (UK) formalism) will offer not only accurate and resilient design but also reconfigurability in that G&C algorithms can easily be modified to suit a wide spectrum of OSAM applications. ControlX team will also consider the feasibility of hardware implementation. The selection of sensors, actuators and onboard computers will be an important trade-off between among size, weight, and power (SWaP) constraints, reliability, and computing performance. A real-time operating system (RTOS) is planned to meet timing and memory management constraints, partitioning hardware resources to control software application interactions. An analysis suite for the autonomous system implementation, based on system modeling and learning techniques, will provide onboard analysis, enabling decision-making as to whether the system can continue to meet mission requirements.

PI: Morad Nazari
Co-PIs: K. Merve Dogan and Alan Lovell
Dates: 2/2023-5/2024
Funding: Air Force, Direct to Phase 2 with ControlX, $450K

A new era of affordable space flight, satellite refueling, on-orbit inspection, orbit transfer and end-of-life servicing has begun as a result of the space industry's continued focus on safe, resilient and adaptable space vehicles. These developments have laid the groundwork for assembly and manufacturing in orbit or space for potential use in active debris removal, reuse and recycling of materials. Advanced navigation and control technologies are required to ensure and lengthen the mission life cycles of these orbital assets, which include launch vehicles, satellites and space stations. Orbit/attitude determination, relative motion, robot manipulator kinematics and spacecraft rendezvous/docking can benefit from new advances in geometric mechanics Udwadia-Kalaba, adaptive control, learning, sensor fusion, computer vision and data communication. These efforts aim to equip future enterprises with the ability to perform in-space servicing and maintenance (ISAM) and on-orbit servicing and maintenance (OSAM) of failed or damaged space assets, as well as in-space manufacturing and platform assembly. However, the ability to validate individual hardware and software components of these technologies on a large scale is still in its early stages. Thus, the goal of this research is to establish an effective experimental testbed for the validation of autonomous ISAM/OSAM systems.

This project, which is funded by NASA Kennedy Space Center, will demonstrate the capability of an electrostatic dust shield, developed by NASA/KSC engineers, to remove dust from the lens of a camera after impact on the lunar surface. Laboratory tests will confirm the experiment design, followed by a flight to the lunar surface in early 2022.

Researchers

Troy Henderson
Aerospace Engineering Department
Ph.D., M.S., Texas A&M University

This project, funded by Intuitive Machines, develops and demonstrates algorithms for detecting and avoiding areas of large rocks and high slopes for a lunar lander. Preliminary work uses an optical camera and future work will include a lidar sensor. These algorithms will be tested in simulation, tested in laboratory experiments and demonstrated on a lunar lander flight mission.

Researchers

Troy Henderson
Aerospace Engineering Department
Ph.D., M.S., Texas A&M University

This project, funded by Air Force Research Laboratory, seeks to improve orbit estimation methods using advanced image processing techniques applied to images from ground and space-based telescopes. Additional work uses RF signals to estimate orbits of transmitting spacecraft.

Researchers

Troy Henderson
Aerospace Engineering Department
Ph.D., M.S., Texas A&M University

Dates: 1/2021-8/2023
Funding: FAA

This project is funded under the FAA ASSURE program. Unvalidated or unavailable GPS and “ADS-B In” data poses security and safety risks to automated UAS navigation and to Detect and Avoid operations. Erroneous, spoofed, jammed or dropouts of GPS data may result in unmanned aircraft position and navigation being incorrect. This may result in a fly away beyond radio control, flight into infrastructure or flight into controlled airspace. Erroneous, spoofed, jammed or dropouts of “ADSB-In” data may result in automated unmanned aircraft being unable to detect and avoid other aircraft or result in detecting and avoiding illusionary aircraft.

In this project, the research team is investigating different strategies to mitigate such risks and proposing methodologies to increase safety of UAS operations within the National Airspace. Several topics related to this project include simulation of dynamic systems, artificial intelligence, flight testing of UAS and hardware implementation.

Researchers

Hever Moncayo
Aerospace Engineering Department
Ph.D., West Virginia University

Dates: 1/2021-8/2023
Funding: FAA

This project is funded under the FAA ASSURE program. Certain small UAS (sUAS) Beyond Visual Line of Sight (BVLOS) operations, such as structural inspection, may be in close proximity to structures that are collision hazards for manned aircraft. These types of operations that are in close proximity to manned aviation flight obstacles such that they provide significant protection from conflicts and collisions with manned aircraft are termed “shielded” operations. This effort is intended to identify risks and recommend solutions to the FAA that enable shielded UAS operations. Several topics related to this project include simulation of dynamic systems, simulation environment programming, guidance, control and dynamics, and hardware implementation.

Researchers

Hever Moncayo
Aerospace Engineering Department
Ph.D., West Virginia University

PI: Morad Nazari
Co-PIs: Troy Henderson and Richard Prazenica
Dates: 8/2021-7/2024
Funding: a.i. Solutions, Inc. and NASA

This research project will continue the development of a special Euclidean (SE(3))-based rigid body pose estimation scheme for unknown moments of inertia in a spacecraft from the successful implementation of a Phase I modeling framework. The specific objectives of the second phase of this project are to advance the TRL of the SE(3) framework/technology from TRL 1-2, to TRL 3, for two specific applications: 1) Optimizing Rendezvous, Proximity Operations and Docking (RPOD) for a trash-filled logistics vehicle and 2) rapid calculation of slosh dynamics in the upper stage of a launch vehicle (LV). The TRL will be advanced through analytical demonstration of the RPOD and Slosh applications in a proof-of-concept simulation environment. This estimator design will a) account for translation rotation coupling, b) avoid singularity or non-uniqueness issues, c) gain a high level of convergence, and d) account for system uncertainties. This NASA proposal identifies a critical knowledge gap: The commonly used attitude parameterization sets (APSs) can result in singularity or non-uniqueness issues.

PI: Morad Nazari
Co-PI: Daewon Kim
Dates: 9/2022-9/2023
Funding: Florida Space Grant Consortium, NASA

This project would build on previous research that developed the dynamics formulation and control of a rigid-flexible system. A cantilevered beam attached to a rotating central body is considered and analyzed through the finite element method. A set of matrix differential equations are obtained to describe the dynamic behavior of the system, and a control law based on a Lyapunov function is obtained and applied to the system. The development of this dynamics formulation and control also considers the rigid-flexible coupling present in the system. The control law is designed such that the system can achieve and maintain a set of desired states for the central rigid body and flexible structure. The experimental measurements obtained from the implementation of FOS sensors on the flexible body and inertial sensors on the rigid body will be utilized as the input in this control design. The research portion of the project is anticipated to require one or two graduate student research assistants and a part-time academic advisor over a one-year period.

Dates: 1/2022-3/2024
Funding: FAA

In this project, which is funded by the FAA ASSURE program, the research team consisting of The Ohio State University, Embry-Riddle Aeronautical University, Mississippi State University, University of North Dakota and Cal Analytics will work together to:

• Identify the key sources of misleading surveillance information produced by airborne and ground-based detect and avoid (DAA) systems. Develop risk modeling and analysis tools to assess the system-wide effects of false or misleading information on alerting and separation, as well as impacts on pilots in command (PIC) and air traffic operators.
• Provide guidance and recommendations for track classification and filter performance and safety requirements to standards bodies, including Radio Technical Commission for Aeronautics (RTCA) and American Society for Testing and Materials (ASTM) DAA working groups, and inform Federal Aviation Administration (FAA) rulemaking on DAA operations.

Current guidance provided by the Federal Aviation Administration has made beyond visual line of sight (BVLOS) missions an executive priority. Key to the success of these missions is the development of DAA systems capable of providing accurate pilot in the loop, or autonomous deconfliction guidance. Current standards for DAA services provided by RTCA and ASTM do not address the requirements for system performance with respect to generation of false or misleading information to the PIC or autonomous response services of the unmanned aircraft system. This research will identify key sources of uncertainty in representative DAA architectures and assess the downstream risks and effects of spurious information on downstream system performance. Additionally, recommendations will be developed for track classification accuracy requirements that provide sufficient safety margins for enabling DAA services in support of BVLOS missions.

Researchers

Richard Prazenica
Aerospace Engineering Department
Ph.D., M.S., University of Florida

Troy Henderson
Aerospace Engineering Department
Ph.D., M.S., Texas A&M University

Morad Nazari
Aerospace Engineering Department
Ph.D., New Mexico State University-Main Campus

Houbing Song
Aerospace Engineering Department
Ph.D., University of Virginia-Main Campus
M.S., The University of Texas at El Paso

Tyler Spence
Aerospace Engineering Department
Ph.D., M.S., Purdue University-Main Campus

Under this research project we will develop an innovative structural health monitoring system for inflatable space habitat structures by integrating nanocomposite piezoresistive sensors

Inflatable structures for space habitats are highly prone to damage caused by micrometeoroid and orbital debris impacts. Although the structures are effectively shielded against these impacts through multiple layers of impact resistant materials, there is a necessity for a health monitoring system to monitor the structural integrity and damage state within the structures. Assessment of damage is critical for the safety of personnel in the habitat, as well as predicting the repair needs and the remaining useful life of the habitat. We are developing a unique impact detection and health monitoring system based on hybrid nanocomposite sensors composed of carbon nanotube sheet and coarse graphene platelets. An array of these sensors sandwiched between soft good layers in a space habitat can act as a damage detection layer for inflatable structures. We will further develop algorithms to determine the event of impact, its severity, and location on the sensing layer for active health monitoring.  Our sensor system will be tested in the hypervelocity impact testing facility at UDRI in future.

Research Dates

08/01/2016 to 05/01/2019

Researchers

Daewon Kim
Aerospace Engineering Department
Ph.D., Virginia Polytechnic Institute and State University

Sirish Namilae
Aerospace Engineering Department
Ph.D., Florida State University

This study is evaluating what initial conditions can activate cubic slip planes, then the level of accommodation and strain homogenization within the grain, and how a given initial condition affects the material behavior when subjected to operational cyclic loads under high temperature.

Ni-based super alloys are widely used in turbine engines mainly due to its high strength and fatigue resistance at elevated temperatures. One hypothesis to explain its atypical characteristic among metals is that a cross-slip mechanism is in place. The activation of {100} cubic slip systems along of the octahedral slip planes {111} in Ni-based superalloys has been verified when under high strain and  temperature. The material would exhibit a more homogeneous strain distribution and less strain localization. We seek for the ideal precondition that will improve the endurance of Ni-based superalloy (IN 718) samples subjected to operational loading. We evaluate the initial conditions that activate cubic slip planes, the level of accommodation, and strain homogenization within the grain. With focus on the deformation mechanism, the sample microstructure can be fully characterized by electron backscatter diffraction (EBSD) and the slip systems, after the applied pre-condition, can be tracked via digital image correlation (DIC).

Accomplished tasks:

(a) samples’ manufacturing, (b) sample polishing and preparation, (c) furnace installation and operational tests, (d) development of laboratory procedures, equipment and microscopes (optical and SEM), (d) calibration and controller fine tuning for the MTS tensile testing machine, and (e) fatigue test with several specimens, including control samples and modified pre-conditions

Next steps:

Characterization of the microstructure of tested specimens under special conditions via EBSD to identify the slip planes and confirm or not the activation of cubic slip systems.

Research Dates

08/16/2019

Researchers

Alberto Mello Jr.
Aerospace Engineering Department
Ph.D., The University of Texas at Austin

This project is in partnership with Gulfstream Aerospace Corporation under MMSE program.

Birds pose a major threat to aviation. Bird impact can lead to significant damage of the aircraft and can be sometimes catastrophic. For a damage tolerant design of an aircraft structure, the structure has to fulfill the airworthiness specifications prescribed by FAA or EASA. 

According to FAR 25, Sub-part 25.571, leading-edge structures of large transport aircraft have to withstand an impact with a 4 lb (1.81 kg) bird (8 lb (3.62kg) for empennage leading edge) when the velocity of the airplane relative to the bird along the airplane's flight path is equal to its cruising speed (Vc) at sea level or 0.85 (Vc) at 8,000 feet, whichever is more critical.

When a bird impacts the structure, it either slides off of the impacted surface causing less damage or it creates a dent or hole due to penetration into the structure, causing significant damage. The behavior of the bird upon the impact depends on the geometrical characteristics of the structure and the velocity at which the bird impacts. When split upon impact, it results in low impact forces and thus less damage. The impact forces are higher when the bird doesn’t split upon the impact which causes more damage to the target structure as the impact forces are directly proportional to the mass of the bird.

Bird strike tests are very expensive and their number in the engine development programs should be minimized. Numerical simulations help reduce a significant amount of testing by providing valuable information in the design process. This thesis aims to develop a model using smooth particle hydrodynamics (SPH) method for analyzing aircraft leading edges for bird strikes that will correlate well with the test results and subsequently, apply the method to study the effect of the leading edge radius on the behavior of the bird (split/not split) upon the impact.

The objective is to generate sufficient data through numerical analysis to confirm the “one inch radius split/no split dividing line”, and to validate the empirical formulas used to calculate the impact forces. Overall, the goal is to save both time and money for the future generation aircraft by minimizing or eliminating the bird strike tests.

Research Dates

08/16/2021 to 05/15/2022

Researchers

Alberto Mello Jr.
Aerospace Engineering Department
Ph.D., The University of Texas at Austin

James J Pembridge
Engineering Fundamentals
Ph.D., M.A., B.S., Virginia Polytechnic Institute and State University

This research aims to establish the effect of hole cold expansion on fatigue life of pre-cracked material under aggressive environment.

This research investigates the relationship between crack propagation and secondary crack initiation in aluminum alloys with cold worked holes subjected to cyclic loads to determine the impact on fatigue life of joints in presence of aggressive environment. We work with experiments and analysis of fatigue life of bolted joints with coldworked holes in presence of galvanic corrosion. This investigation is examining the effect of local plastic deformation and localized galvanic corrosion on small cracks and fatigue life of bolted joints. The benefits of cold work are well known and its application is widely used in new and repaired structures, even in crack arrester holes. However, coldworked holes are usually fastened to dissimilar materials, what may induce localized galvanic corrosion. When applied in the field, damaged material removal in a cold work procedure may be limited to a maximum allowable diameter for reaming and finishing, what may leave micro/small cracks on the strained region. To completely understand the effect of initial cracks as a function of initial plastic deformation level in a coldworked hole it is necessary to fully evaluate strain distribution during and post cold work with microscopic detail. In a first approach, we have analyzed (FEM and classic analysis) and measured strain distribution during the process using digital image correlation (DIC). In the next step, we have tested specimens under fatigue. Pre cold work induced micro cracks was monitored in-situ via digital optical microscopy. In sequence, the coldworked holes were filled with a dissimilar material fastener in saline environment and the impact of galvanic corrosion on crack growth rate was determined for AA 2024-T3.

In a next step, we will further investigate the formation of critical secondary cracks. The probable cause could be a local corrosion around cathodic precipitates, but a detailed study is necessary to confirm this hypothesis. The tested samples must be prepared for use in scanning electron microscope (SEM) to identify the local pit formation at the plate edge, find the point of crack initiation, and determine the propagation path. Using striation counting technique, we may be able to estimate the number of cycles to failure and, consequently, the time necessary for the crack initiation under aggressive environment. Additionally, we will plan to use and analyze a special ceramic coating to mitigate galvanic corrosion effect on loaded components.

Research Dates

08/16/2019

Researchers

Alberto Mello Jr.
Aerospace Engineering Department
Ph.D., The University of Texas at Austin

This Project is founded by National Science Foundation, under REU site. This project aims to educate students and promote scientific research in materials and aerospace science that encompasses not only building lighter and smarter materials for aerospace applications but also understanding the impact of the space environment on physiological and biological changes.

This Site will focus on multidisciplinary research in aerospace engineering, chemistry, and applied space biology with a goal of improving future space materials science and human diagnostic technology by exposing students to the challenges in these areas and the research going on to solve them. Undergraduate students for a ten-week summer will be recruited for the program. The student recruitment will start in Nov 2021 and the first summer research will be held in the period of May 16 to July 18, 2022.

The ERAU-REU program is dedicated to the ideals of diversity, equity, accessibility, and inclusion and we ensure a safe and comfortable environment for all scholars. Please contact us if you have any questions or concerns about the housing accommodations or other aspects of the program.

Students from underrepresented groups in the sciences, veterans, disabled, or are early in their undergraduate coursework (rising sophomores or juniors) are especially encouraged to apply.

Research Areas:

1. Additive Manufacturing of Shape-Stabilized Phase-Change Materials (PCMs)

Mentor: Prof. Sandra Boetcher

The goal of the proposed research is to manufacture shape-stabilized PCMs via additive manufacturing.

2. Space Radiation: Study of Intracellular Reactive Oxygen Species

Mentor: Prof. Hugo Castillo

The goal of this project is to produce a standardized technique to measure the intracellular concentration of ROS in different species of bacteria and yeast, in relation to chronic exposure to sub-lethal doses of ionizing radiation using a low-dose gamma irradiator allowing to quantify the oxidative stress status of the cell concerning DNA damage.

3. Investigating Micro- and Nano-Plastics in the Confined Environment of Space Flight.

Mentor: Prof. Marwa El-Sayed

The proposed study aims to characterize atmospheric MNP in indoor environments. The goals of the study are 1) identification of the sizes, shapes and size distribution of MNP in the atmosphere, 2) characterization of the chemical composition of atmospheric MNP, 3) determination of the degradation processes and 4) identification of the health issues associated with these particles.

4. Investigation of Space Biomechanics and Additive Manufacturing of the Orthopedics

Mentor: Prof. Victor Huayamave

The participants will learn about (1) current state of space biomechanics research, (2) segmenting anatomical images to develop finite element models, and (3) 3D printed components using additive manufacturing. The computational pipeline will be introduced to the predictive power of the FEM to assess the structural integrity of the hip joint under microgravity conditions.

5. Fabrication of a Flexible, Stretchable, and Self-Healable Platform for Aerospace Applications

Mentors: Prof. Foram Madiyar, Prof. Daewon Kim

The goal of this project is to investigate the use of polymers not only having tunable electrical and thermal properties, but also reversible bond chemistry that imparts materials high stretchability, exceptional toughness, and self-healability.

6. On-Site Biomarker Sensing using Flexible Transistors on Skin

Mentor: Prof. Foram Madiyar

The goal of the project is to design a wearable technology for the real-time screening, diagnosis and multiplex detection of different biomarkers.

7. Biofidelic Piezoresistive Nanocomposite Multiscale Analysis

Mentor: Prof. Sirish Namilae

In the proposed research, we will further engineer the electro-mechanical response of the structure through (a) varying the constituents in the silicone matrix and (b) engineering the interface mechanical properties in the core layer.

8. Fractography using Scanning Electron Microscopy

Mentor: Prof. Alberto Mello

This research aims to cover scanning electron microscope (SEM) operation, including energy dispersive spectroscopy (EDS) and stress analysis. The student will cut and prepare fractured specimens, observe the crack surface under SEM to identify the local pit formation at the plate edge, find the point of crack initiation, and determine the propagation path.

9. Investigation of Photoresponsive and Thermally Stable Monomeric Structures for Space Applications

Mentor: Prof. Javier Santos

The goal of the project is to investigate the photoresponsive and thermally stable monomeric structures to sense damage, fractures, and changes to space infrastructures.

10. Investigating Methods to Minimize the Gap between Pre and Post-Space Flight Syndrome

Mentor: Prof. Christine Walck

We propose to design an optimized lower extremity force acquisition system (LEFAS) that integrates with a lower-body negative pressure (LBNP) box and subject-specific protocols for improved fitness results by taking a computationally simulated optimization approach.

Research Dates

05/16/2021 to 07/31/2024

Researchers

Foram Madiyar
Physical Sciences Department
Ph.D., Kansas State University
B.S., Pune University

Alberto Mello Jr.
Aerospace Engineering Department
Ph.D., The University of Texas at Austin

In this work, a design optimization is being investigated considering possible hydrodynamic and structural advantages aiming to reduce the structure weight factor, with a trade-off between fluid dynamics and structural aspects.

Seaplanes are known to have mandatory design characteristics that lead to disadvantages in comparison to landplanes what limit their use as regular passenger commuters. The main design points to consider are that seaplanes have higher structure weight factor due to hull with its specific shape that creates higher drag than the fuselage of a landplane. They also have higher trim drag because of the need of placing the propellers far from the water surface. All these drawbacks reduce payload capability of seaplanes. In this work, a design optimization will be investigated considering possible hydrodynamic and structural advantages aiming to reduce the structure weight factor, with a trade-off between fluid dynamics and structural aspects, increasing payload capability. An optimized structure may lead to a more effective use of seaplanes as cargo or passenger commuters. A SEAMAX M-22 currently being assembled in the ERAU Research Park hangar will be used for result comparisons.

Research Dates

08/16/2021 to 07/31/2022

Researchers

Alberto Mello Jr.
Aerospace Engineering Department
Ph.D., The University of Texas at Austin

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