1-4 of 4 results
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Maritime RobotX Challenge
PI Eric Coyle
CO-I Patrick Currier
CO-I Charles Reinholtz
CO-I Brian Butka
The Maritime RobotX Challenge entails the development and demonstration of an autonomous surface vehicle (ASV). Embry-Riddle is one of three U.S. schools selected to compete in the challenge, which is co-sponsored by the Office of Naval Research (ONR) and the Association for Unmanned Vehicle Systems International (AUVSI) Foundation.
The 2014 ERAU platform, named Minion, is a 16-foot fully-autonomous Wave Adaptive Modular Vessel (WAM-V) platform and is registered as an autonomous boat in the state of Florida. Minion's development currently focuses on autonomous tasks of buoy channel navigation, debris avoidance, docking, target identification and sonar localization. To accomplishing these tasks, the team has developed as set of system software nodes including state estimation, object classification, mapping and trajectory planning. These nodes run in parallel across a set of networked computers for distributed processing. Minion's propulsion system is centered around a set rim-driven hubless motors attached to articulated motor pods. This design reduces the risk of entanglement, and provides consistent thrust by maintaining motor depth in rough seas.The group is currently developing the 2016 platform for the competition
Categories: Faculty-Staff
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Composite Wind Turbine Blade
PI Sathya Gangadharan
The world's primary energy needs are projected to grow by 56% between 2005 and 2030, by an average annual rate of 1.8% per year (International Energy Agency, 2012). Energy policy has confirmed the improvement of the environment sustainability of energy as a primary objective also though increasing use of renewable sources (Increasing Wind Energy's contribution to U.S. Electricity supply, 2008).
Wind energy research is being followed in the world as an alternative to fulfill increasing electricity power demand, United State Department of Energy is aiming to expand the wind power in the U.S. Currently, 15.4 GW of power are installed and operational, with an expected growth the U.S. wind capacity will be at 310 GW by 2030, representing 20% of the nation's power needs (Increasing Wind Energy's contribution to U.S. Electricity supply, 2008).
Research on composite wind turbine blade carried out in Embry-Riddle is described below:
FLUID-STRUCTURE INTERACTION AND MULTIDISCIPLINARY DESIGN ANALYSIS OPTIMIZATION OF COMPOSITE WIND TURBINE BLADE Mission:
To maximize aerodynamic efficiency and structural robustness while reducing blade mass and total cost.A multidisciplinary design analysis optimization (MDAO) process is defined for a composite wind turbine blade to optimize its aerodynamic and structural performance by developing a fluid-structural interaction (FSI) system. MDAO process is defined in conjunction with structural and aerodynamic performance of the blade which is divided into three steps and the design variables considered are related to the shape parameters, twist distributions, pitch angle, material and the relative thickness based on number of composite layers at different blade sections. Maximum allowable tip deformations, modal frequencies and allowable stresses are set as design constraints. Airfoil performance is predicted with 2D airfoils analysis, while 3D CFD analysis is performed by ANSYS CFX software. A parameterized finite element model of the blade created in ANSYS ACP composite prepost and used to define the composite layups of the blade. The results of the CFD and the structural analysis are used for the optimization process accompanied by the cost estimation to obtain a compromised solution between aerodynamic performance and structural robustness. For the MDAO process number of design of experiments (DOEs) is defined by G optimality method and a response surface is created. Sensitivity analysis is performed to observe the impact of input parameter on each output parameters for enhanced control of the MDAO process. Further, to improve aerodynamic performance of the blade, new design approach with modified Tip (winglet) and rotor section is studied and substantial improvement in power generated over high quality baseline wind turbine blade is presented.
A BASELINE STUDY AND CALIBRATION FOR MULTIDISCIPLINARY DESIGN OPTIMIZATION OF HYBRID COMPOSITE WIND TURBINE BLADE
Preliminary baseline finite element (FE) model calibrations and evaluations are developed to assist and guide multidisciplinary design optimization (MDO) of a large-scale hybrid composite wind turbine blade. The weight, displacement, and failure index are compared and used for calibration purposes. In addition, a cost estimation model is calibrated for labor hour, as well as labor cost, material cost and total cost. Stability of baseline wind turbine blade against harmonic resonance due to rotor rotation is validated by finite element analysis (FEA). A MDO process is proposed using the calibrated FE and cost estimation models. The MDO optimizes multiple objectives such as blade length, weight, manufacturing cost, and power production. For this analysis, the turbine blade is divided into regions and the sequence of hybrid laminate layup for each region is considered as design variables. Extreme wind condition for rotor rotation and rotor stop condition is considered as the applied load on the blade. The designed structural strength and stiffness are demonstrated to withstand the loads due to harmonic excitation from rotor rotation. A process of design procedure for obtaining an optimum hybrid composite laminate layup and an optimum blade length of a wind turbine blade structure is developed in this research.
Categories: Faculty-Staff
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Fuel Slosh
PI Sathya Gangadharan
2014 marks the eleventh year of Fuel Slosh studies that have been carried out at Embry-Riddle Aeronautical University. Initially funded by NASA Graduate Student Research Program (GSRP) along with Southwest Research Institute, the research was started by Keith Schlee, a graduate student, under the guidance of Dr. Sathya Gangadharan, professor at Embry-Riddle.
The research involved extensive theoretical and computational analysis. A fuel slosh test rig was set up at the structures lab for the students and researchers to conduct various experiments and validate their results.This research has evolved from the study of fuel slosh to the effect of diaphragms and baffles on slosh behavior and to the use of smart materials in actively damping the slosh. Tests on effectiveness of damping have also been carried out at NASA's Spinning Slosh Test Rig (SSTR) located at the Southwest Research Institute (SwRI) in San Antonio, Texas. Research works are frequently published at but not limited to American Institute of Aeronautics and Astronautics (AIAA), American Society of Mechanical Engineers (ASME), NASA Technical Reports Server (NTRS) and so on.A gist of some of the research works in Fuel Slosh carried out at Embry-Riddle is described below from the previous to the current on-going research:(Note: Only selective research works are mentioned below, for complete list of fuel slosh research works contact Dr. Sathya Gangadharan)
MODELING AND PARAMETER ESTIMATION OF SPACECRAFT FUEL SLOSH MODE
Mission:The research is directed toward modeling fuel slosh on spinning spacecraft using simple pendulum analogs. The pendulum analog will model a spherical tank with no PMD's. An electric motor will induce the motion of the pendulum to simulate free surface slosh. Parameters describing the simple pendulum models will characterize the modal frequency of the free surface sloshing motion. The one degree of freedom model will help to understand fuel sloshing and serve as a stepping stone for future more complex simulations to predict the NTC accurately with less time and effort.
A CFD APPROACH TO MODELING SPACECRAFT FUEL SLOSH
Mission: By using a Computational Fluid Dynamics (CFD) solver such as Fluent, a model for this fuel slosh can be created. The accuracy of the model must be tested by comparing its results to an experimental test case. Such a model will allow for the variation of many different parameters such as fluid viscosity and gravitational field, yielding a deeper understanding of spacecraft slosh dynamics.
MODELING OF FREE-SURFACE FUEL SLOSH IN MICROGRAVITY FOR OFF-AXIS SPACECRAFT PROPELLANT TANKS
Mission: MATLAB SimMechanics fuel slosh model can be used to estimate slosh parameters and predict dynamic effects on dependent systems. Comparative flight data was acquired by spinning a mock spacecraft with partially filled propellant tanks in a microgravity environment. Empirical and simulated NTC's are compared to validate a SimMechanics fuel slosh model.
A COMPUTATIONAL AND EXPERIMENTAL ANALYSIS OF SPACECRAFT PROPELLANT TANKS IMPLEMENTED WITH FLEXIBLE DIAPHRAGMS
Mission:The main objective of this research is to validate computational modeling of fuel slosh scenarios so that it may become the primary means of testing fuel slosh scenarios during initial spacecraft design. By expanding on past research objectives, this research aims at complementing the pre-existing data with new data from added computational and experimental simulations. Additionally, this research aims at conducting an extensive study of the computational fuel slosh models used in this investigation. The current research investigation presents detailed results of the fluid behavior within the tank and initiates an even more extensive investigation of fluid behavior for future fuel slosh research studies at ERAU.
AN INVESTIGATION OF BAFFLES AND ASPERITIES ON SLOSH BEHAVIOR IN PROPELLANT TANKS OF SPACECRAFT AND LAUNCH VEHICLES
Mission:The focus of this research is to investigate the fuel slosh behavior in propellant tanks. Different types of baffles and hemispherical asperities are introduced inside the tank to characterize the slosh behavior of the fluid. The modeling and the analysis of slosh is done using the CFD solver ANSYS CFX for tanks with and without baffles and for tanks with hemispherical asperities. Physical models are fabricated for experimental testing using the fuel slosh test facility at Embry Riddle Aeronautical University. Using the single axis linear actuator and fuel tank set up in the test facility, experimental results are obtained with and without baffles. The experiment and CFD modeling results are compared.
SLOSH DAMPING WITH FLOATING ELECTRO-ACTIVE MICRO-BAFFLES
Mission: Embedding floating micro-baffles with an electro-active material such that the baffle can be manipulated when exposed to a magnetic field preserves the benefits of both floating and static baffle designs. Activated micro-baffles form a rigid layer at the free surface and provide a restriction of the fluid motion. Proposed micro-baffle design and magnetic activation source method along with proof-of-concept experiments comparing the scope of this research to previous PMD methods are presented. A computational fluid dynamics approach is outlined. Preliminary proof-of-concept testing indicates floating electro-active micro-baffles reduce the damping time of sloshing by up to 88% as compared to the same slosh condition with the absence of any PMDs.
DEVELOPMENT OF A MAGNETOSTRICTIVE PROPELLANT MANAGEMENT DEVICE (MSPMD) FOR HYBRID ACTIVE SLOSH DAMPING IN SPACECRAFT APPLICATION
Mission:To study the use of a hybrid Magnetostrictive membrane as a Magnetostrictive Propellant Management Device (MSPMD) to actively control the free surface effect and reduce fuel slosh.. The viability of merging existing diaphragm membrane aka Propellant management device (PMD) with a magnetostrictive inlay embedded with the Terfenol-D matrix / MR-Fluid allows us to actively control the membrane during in-flight conditions. Apart from the development, analysis on the control of the hybrid active membrane and the use of the same to dampen fuel slosh is also performed in order to establish the proof of concept. During the development process of the hybrid active membrane, the geometric dependency of the meta-smart structure is analyzed to optimize the membrane shape, size and material.
Categories: Faculty-Staff
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UAS Ground Collision Severity Evaluation
PI Feng Zhu
CO-I Eduardo Divo
CO-I Victor Huayamave
Increased use of UAS requires an in-depth understanding of the hazard severity and likelihood of UAS operations in the NAS. Due to their distinct characteristics (e.g. size, weight and shape) with manned aircraft systems, UAS operations may pose unique hazards to other aircraft and people on the ground.
Up to date, the studies on the UAS ground collision are still very much limited, particularly the scenario of impact between UAS and human body on the ground. Therefore, it is necessary to determine lethality thresholds for UAS using characteristic factors that affect the potential lethality of UAS in collisions with other objects, particularly human body on the ground. The objectives of this study are (1) to analyze the response and failure behavior of several typical UASs impact with human body on the ground; and (2) establish the damage threshold of UAS and its correlation with the key parameters in the crash accidents (e.g. shape, size and materials of UAS; impact energy and impulse etc.). To achieve this goal, advanced computational modeling techniques (e.g. finite element method/FEM) will be used to simulate the typical UAS/people impact scenarios.Based on the results, a design guidance can be further suggested to improve the crashworthiness of UAS and safety of personnel on the ground.
Conventional 14 CFR system safety analyses include hazards to flight crew and occupants may not be applicable to unmanned aircraft. It is necessary to determine the dedicated hazard severity thresholds for UAS and identify the key factors that affect the potential severity of UAS in collisions with other aircraft on the ground or in airborne encounters as well as collisions with people on the ground. These severity thresholds will help determine acceptable corresponding system failure levels in accordance with the applicable 14 CFR requirements (for example 14 CFR 23.1309 and 14 CFR 25.1309).
Categories: Faculty-Staff
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