21-30 of 82 results

  • Understanding the Coupled Dynamics of Particles and Wall Turbulence

    PI Ebenezer Gnanamanickam

    ​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.

    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.

    Categories: Faculty-Staff

  • Understanding the Coupled Interactions Between Hair-Like Micromechanoreceptors and Wall Turbulence

    PI Ebenezer Gnanamanickam

    ​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.

    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.

    Categories: Faculty-Staff

  • Aeroelastic Gust-Airfoil Interaction Numerical Studies

    PI Vladimir Golubev

    The project conducted in collaboration with WPAFB and Eglin AFB AFRL scientists over the past 8 years employs DOD HPC and ERAU computer facilities to conduct high-fidelity, low-Reynolds, aeroelastic gust-airfoil interaction studies to model unsteady responses and their control for small UAVs operating, e.g., in highly unsteady urban canyons.

    The focus is on modeling airfoil interactions with canonical upstream flow configurations including time-harmonic and sharp-edge gusts, vortices and synthetic turbulence with prescribed characteristics tailored to a specified unsteady flight-path environment. Note that this and other listed projects that include noise predictions and noise/flow control components are partially supported by Florida Center for Advanced Aero Propulsion (FCAAP) in these efforts

    Categories: Faculty-Staff

  • Self-Sustained Flow-Acoustic Interactions in Airfoil Transitional Boundary Layers

    PI Vladimir Golubev

    CO-I Reda Mankbadi

    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 PhD and MSAE students both in U.S. and France.

    Categories: Faculty-Staff

  • Synthetic Jet-Based Robust MAV Flight Controller

    PI Vladimir Golubev

    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

    Categories: Faculty-Staff

  • Wake Vortex Safety Analysis in the Context of UAS Integration in the NAS

    PI Vladimir Golubev

    ​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 (UAS). 



    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.

    Categories: Faculty-Staff

  • Demonstration of an Electrostatic Dust Shield on the Lunar Surface

    PI Troy Henderson

    This project 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.



    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

    Categories: Faculty-Staff

  • Hazard Detection and Avoidance for Lunar Landing

    PI Troy Henderson

    This project develops and demonstrates algorithms for detecting and avoiding areas of large rocks and high slopes for a lunar lander

    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.

    Categories: Faculty-Staff

  • Improved Image Processing for Orbit Estimation

    PI Troy Henderson

    This project seeks to improve orbit estimation methods using advanced image processing techniques applied to images from ground and space-based telescopes.

    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.

    Categories: Faculty-Staff

  • Multiscale Computational and Experimental Framework to Elucidate the Biomechanics of Infant Growth

    PI Victor Huayamave

    There is currently a lack of biomechanical quantification of growth and development because: (1) there is no generic musculoskeletal infant model, and (2) the lack of infant data in the literature.

    An infant’s spontaneous movements generate forces that are constantly acting on the joints and can affect the morphology and development of soft bone. Using experimental motion capture data, statistical shape modeling, and multi-scale musculoskeletal mechanobiological models, we will be able to predict the complex adaptation of the joint to biomechanical factors, thus providing a biomechanical basis for improved prevention and treatment of developmental disorders. This project pioneers the development of solutions that improve intervention and outcomes of conditions such as scoliosis, spina bifida, clubfoot and developmental dysplasia of the hip. The model provides a non-invasive three-dimensional approach to study the dynamics of human movements using biomechanical parameters that are difficult or impossible to examine using physical experiments alone. Our proposed research will advance pediatric movement science and will uncover the underlying mechanisms involved in the maturation of the hip joint during early development. Results from the proposed research will: (1) Provide experimental data and computational models that can serve as the basis for developing innovative solutions for infant developmental disorders; (2) Develop innovative tools to aid clinicians, pediatricians and physical therapists when managing joint disorders; (3) Identify factors that drive and regulate growth early in life that may have long-term benefits for prevention of early arthritis. Each of these contributions is significant given that joint disorders such as developmental dysplasia of the hip underlie around 29% of all primary hip replacements in adults.

    Categories: Faculty-Staff

21-30 of 82 results