2u Cubesat Structural Design And Integration,
2017
Morehead State University
2u Cubesat Structural Design And Integration, Yevgeniy Byeloborodov
Morehead State Theses and Dissertations
A thesis presented to the faculty of the College of Science, Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Yevgeniy Byeloborodov on April 18, 2017.
Optimal Configurations For Aerosol Monitoring With Multi-Rotor Small Unmanned Aerial Systems,
2017
Air Force Institute of Technology
Optimal Configurations For Aerosol Monitoring With Multi-Rotor Small Unmanned Aerial Systems, Inna D. Chavez
Theses and Dissertations
Applicability of aerosol sampling on multi-rotor unmanned aerial systems (UAS) platform was investigated. Multi-rotor UAS have impacts of wind speed, turbulence, and orientation possibly contributing to sampling bias. The SKC IMPACT sampler, Tecora C.A.Th.I.A., and modified three-dimensionally printed Universal Inlet for Airborne-Particle Size-Selective Sampling were selected based on particle size-selectivity and operational independence to wind. Airflow visualizations concluded that below UAS fuselage was optimal sampler placement. Tests were conducted with Arizona Road Dust in a still-air chamber, and aerosolized sugar in a wind tunnel. Inlet mounting was evaluated in, upright, upside-down, and horizontal orientations. Horizontal orientations of all inlets resulted …
Optimal Design Of A Hexakis Icosahedron Vacuum Based Lighter Than Air Vehicle,
2017
Air Force Institute of Technology
Optimal Design Of A Hexakis Icosahedron Vacuum Based Lighter Than Air Vehicle, Joseph R. Schwemmer
Theses and Dissertations
Due to the rising cost and scarcity of helium, new methods to ensure buoyancy for lighter-than-air vehicles (LTAVs) are being sought. One alternative under study uses an internal vacuum to reduce the weight to buoyancy ratio. It's a novel approach; however, the vacuum presents challenges for the vehicle's structure. The structure must have minimum mass while preventing buckling and excess stress throughout the frame and membrane. The structure under analysis is a hexakis icosahedron with a membrane covering. Achieving minimum mass involves optimizing the structure under the loading conditions. Finite-element analysis (FEA) and direct-search methods are employed, providing an optimal …
Surrogate Modeling Of Ultrasonic Simulations Using Data-Driven Methods,
2017
Missouri University of Science and Technology
Surrogate Modeling Of Ultrasonic Simulations Using Data-Driven Methods, Xiaosong Du, Robert Grandin, Leifur Leifsson
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Ultrasonic testing (UT) is used to detect internal flaws in materials and to characterize material properties. In many applications, computational simulations are an important part of the inspection-design and analysis processes. Having fast surrogate models for UT simulations is key for enabling efficient inverse analysis and model-assisted probability of detection (MAPOD). In many cases, it is impractical to perform the aforementioned tasks in a timely manner using current simulation models directly. Fast surrogate models can make these processes computationally tractable. This paper presents investigations of using surrogate modeling techniques to create fast approximate models of UT simulator responses. In particular, …
Professional Pilot Commercial Off-The-Shelf (Cots) Efb Usage, Policies And Reliability,
2017
Middle Tennessee State University
Professional Pilot Commercial Off-The-Shelf (Cots) Efb Usage, Policies And Reliability, Tyler A. Babb
International Journal of Aviation, Aeronautics, and Aerospace
Electronic Flight Bags (EFBs) have flooded the aviation industry. Commercial off-the-shelf (COTS) tablets are now commonly used by pilots as EFBs. Operators use EFBs for ease of use, faster access to information, to remove weight from the aircraft, and to increase pilots’ quality of life. Identifying trends in EFB usage among professional pilots could benefit operators and universities with flight training programs. EFB policies and procedures may vary among operators but achieve FAA compliance. This study identified these policies and procedures. The types of devices and software vary, and identifying these devices and software could be useful. This research used …
Optimal Trajectory Determination And Mission Design For Asteroid/Deep-Space Exploration Via Multibody Gravity Assist Maneuvers,
2017
San Jose State University
Optimal Trajectory Determination And Mission Design For Asteroid/Deep-Space Exploration Via Multibody Gravity Assist Maneuvers, Sean Fritz, Kamran Turkoglu
Faculty Publications
This paper discusses the creation of a genetic algorithm to locate and optimize interplanetary trajectories using gravity assist maneuvers to improve fuel efficiency of the mission. The algorithm is implemented on two cases: (i) a Centaur-class target close to the ecliptic plane and (ii) a Centaur-class target with a high inclination to the ecliptic plane. Cases for multiple numbers of flybys (up to three) are discussed and compared. It is shown that, for the targets considered here, a single flyby of Jupiter is the most efficient trajectory to either target with the conditions and limitations discussed in this paper. In …
Expedite Design Of Variable-Topology Broadband Hybrid Couplers For Size Reduction Using Surrogate-Based Optimization And Co-Simulation Coarse Models,
2017
Missouri University of Science and Technology
Expedite Design Of Variable-Topology Broadband Hybrid Couplers For Size Reduction Using Surrogate-Based Optimization And Co-Simulation Coarse Models, Piotr Kurgan, Slawomir Koziel, Leifur Leifsson, Xiaosong Du
Mechanical and Aerospace Engineering Faculty Research & Creative Works
In this paper, we discuss a computationally efficient approach to expedite design optimization of broadband hybrid couplers occupying a minimized substrate area. Structure size reduction is achieved here by decomposing an original coupler circuit into low- and high-impedance components and replacing them with electrically equivalent slow-wave lines with reduced physical dimensions. The main challenge is reliable design of computationally demanding low-impedance slow-wave structures that feature a quasi-periodic circuit topology for wideband operation. Our goal is to determine an adequate number of recurrent unit elements as well as to adjust their designable parameters so that the coupler footprint area is minimal. …
A Method For Evaluating Aircraft Electric Power System Sizing And Failure Resiliency,
2017
California Polytechnic State University, San Luis Obispo
A Method For Evaluating Aircraft Electric Power System Sizing And Failure Resiliency, Cory Kenneth Kross
Master's Theses
With the More Electric Aircraft paradigm, commercial commuter aircraft are increasing the size and complexity of electrical power systems by increasing the number of electrical loads. With this increase in complexity comes a need to analyze electrical power systems using new tools. The Hybrid Power System Optimizer (HyPSO) developed by Airbus SAS is a simulator designed to analyze new aircraft power systems. This thesis project will first provide a method to assess the reliability of complex aircraft electrical power systems before and after failure and reconfiguration events. Next, an add-on to HyPSO is developed to integrate the previously developed reliability …
Design And Construction Of An Optimum Method To Present Uncertainty Of Convective Weather Forecasts To Air Traffic Personnel,
2017
The University of Akron
Design And Construction Of An Optimum Method To Present Uncertainty Of Convective Weather Forecasts To Air Traffic Personnel, Anna K. Selchow, Austin Wright
Williams Honors College, Honors Research Projects
The purpose of this design project was to develop a new weather display for air traffic controllers to utilize that shows the probabilistic hazard information for convective weather forecasts. Multiple iterations of maps were generated and evaluated for overall effectiveness in conveying uncertainty information for convective weather observations and forecasts with the final maps being tested through interviews with retired air traffic personnel. The goal of these maps was to improve upon current convective weather displays to more accurately show uncertainty and probabilistic hazard information to aid the air traffic controllers (ATCs) in providing guidance for aircraft pilots.
Robust Airfoil Design Optimization Using Stochastic Expansions And Utility Theory,
2017
Missouri University of Science and Technology
Robust Airfoil Design Optimization Using Stochastic Expansions And Utility Theory, Xiaosong Du, Leifur Leifsson, Slawomir Koziel
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Efficient and effective robust airfoil design optimization is proposed by integrating stochastic expansions and utility theory. In this work, the stochastic expansions are generated efficiently using non-intrusive polynomial chaos (NIPC) expansions. The robust design problem is formulated using utility functions which transfer a targeted response using a prescribed mathematical function to represent the designers' risk preferences. The proposed approach is demonstrated using examples of lift-constrained airfoil drag minimization in transonic viscous flow using the Mach number as an uncertain variable in the range of 0.70 to 0.75. The results are compared with the common problem formulation for robust design of …
Aerodynamic Design Of A Rectangular Wing In Subsonic Inviscid Flow By Surrogate-Based Optimization,
2017
Missouri University of Science and Technology
Aerodynamic Design Of A Rectangular Wing In Subsonic Inviscid Flow By Surrogate-Based Optimization, Xiaosong Du, Anand Amrit, Andrew Thelen, Leifur Leifsson, Yu Zhang, Zhong Hua Han, Slawomir Koziel
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The paper presents results of aerodynamic design of a rectangular wing in subsonic inviscid flow using surrogate-based local and global search algorithms. The aerodynamic design problem is formulated in Benchmark Cases 3 and 6 developed by the AIAA Applied Aerodynamics Discussion Group. Both involve lift-constrained drag minimization at a Mach number of 0.5 with relatively low lift coefficients (0.2625 and 0.375) with several nonlinear constraints and a small number design variables (up to 15). In this work, the local search is performed using variable-fidelity modelling and output space mapping, whereas the global search is performed using approximation-based surrogates. The paper …
Aerodynamic Design Of The Rae 2822 In Transonic Viscous Flow: Single- And Multi-Objective Optimization Studies,
2017
Missouri University of Science and Technology
Aerodynamic Design Of The Rae 2822 In Transonic Viscous Flow: Single- And Multi-Objective Optimization Studies, Anand Amrit, Xiaosong Du, Andrew Thelen, Leifur Leifsson, Slawomir Koziel
Mechanical and Aerospace Engineering Faculty Research & Creative Works
This paper addresses a benchmark aerodynamic design problem proposed by the AIAA Aerodynamic Design Optimization Discussion Group: Drag minimization of the RAE 2822 in transonic viscous flow at a fixed lift coefficient with constraints on the pitching moment coefficient and the cross-sectional area. The single-objective optimization (SOO) problem is solved using surrogate-based optimization (SBO) with the surrogates constructed through output space mapping and variable-resolution Reynolds-Averaged Navier-Stokes computational fluid dynamics models. Improving the implementation of our search algorithms enabled us to obtain the SOO optimal design four times faster than in our prior work in terms of CPU time. To explore …
Airfoil Design Under Uncertainty Using Non-Intrusive Polynomial Chaos Theory And Utility Functions,
2017
Missouri University of Science and Technology
Airfoil Design Under Uncertainty Using Non-Intrusive Polynomial Chaos Theory And Utility Functions, Xiaosong Du, Leifur Leifsson, Slawomir Koziel, Adrian Bekasiewicz
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Fast and accurate airfoil design under uncertainty using non-intrusive polynomial chaos (NIPC) expansions and utility functions is proposed. The NIPC expansions provide a means to efficiently and accurately compute statistical information for a given set of input variables with associated probability distribution. Utility functions provide a way to rigorously formulate the design problem. In this work, these two methods are integrated for the design of airfoil shapes under uncertainty. The proposed approach is illustrated on a numerical example of lift-constrained airfoil drag minimization in transonic viscous flow using the Mach number as an uncertain variable. The results show that compared …
Pareto Ranking Bisection Algorithm For Em-Driven Multi-Objective Design Of Antennas In Highly-Dimensional Parameter Spaces,
2017
Missouri University of Science and technology
Pareto Ranking Bisection Algorithm For Em-Driven Multi-Objective Design Of Antennas In Highly-Dimensional Parameter Spaces, Adrian Bekasiewicz, Slawomir Koziel, Leifur Leifsson, Xiaosong Du
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A deterministic technique for fast surrogate-assisted multi-objective design optimization of antennas in highly-dimensional parameters spaces has been discussed. In this two-stage approach, the initial approximation of the Pareto set representing the best compromise between conflicting objectives is obtained using a bisection algorithm which finds new Pareto-optimal designs by dividing the line segments interconnecting previously found optimal points, and executing poll-type search that involves Pareto ranking. The initial Pareto front is generated at the level of the coarsely-discretized EM model of the antenna. In the second stage of the algorithm, the high-fidelity Pareto designs are obtained through optimization of corrected local-approximation …
Cubesat Adcs Validation And Testing Apparatus,
2016
Western Michigan University
Cubesat Adcs Validation And Testing Apparatus, Jacob Stevens
Honors Theses
The WALI team at Western Michigan University requested a test environment to validate their CubeSat’s de-tumbling control system and hardware. The test environment required a Helmholtz cage and spherical air bearing. The Helmholtz cage provides an adjustable magnetic field to simulate low earth orbit; the spherical air bearing simulates the friction free environment the CubeSat will experience in space. In conjunction, the two components create an adjustable system that simulates a satellite in low earth orbit.
Development Of Fault Tolerant Adaptive Control Laws For Aerospace Systems,
2016
Embry-Riddle Aeronautical University
Development Of Fault Tolerant Adaptive Control Laws For Aerospace Systems, Andres E. Perez Rocha
Doctoral Dissertations and Master's Theses
The main topic of this dissertation is the design, development and implementation of intelligent adaptive control techniques designed to maintain healthy performance of aerospace systems subjected to malfunctions, external parameter changes and/or unmodeled dynamics. The dissertation is focused on the development of novel adaptive control configurations that rely on non-linear functions that appear in the immune system of living organisms as main source of adaptation. One of the main goals of this dissertation is to demonstrate that these novel adaptive control architectures are able to improve overall performance and protect the system while reducing control effort and maintaining adequate operation …
Integration And Qualification Of The P-Pods On The Vega Maiden Flight,
2016
California Polytechnic State University, San Luis Obispo
Integration And Qualification Of The P-Pods On The Vega Maiden Flight, Ryan Nugent
Master's Theses
On February 13, 2012, California Polytechnic State University, San Luis Obispo flew three Poly-Picosatellite Orbital Deployers (P-PODs), carrying seven European University CubeSats sponsored by the European Space Agency (ESA), on the Vega Maiden Flight. This was the first time CubeSats shared a ride to space with other payloads on an ESA-owned launch opportunity. In order to meet launch requirements, it must be proven through proper documentation that the P-POD would operate properly and not interfere with the launch vehicle or other payloads on the mission. This thesis outlines the program flow, required documentation, and issues encountered during the launch campaign …
A New Approach To Modeling Aviation Accidents,
2016
Purdue University
A New Approach To Modeling Aviation Accidents, Arjun Harsha Rao
Open Access Dissertations
General Aviation (GA) is a catchall term for all aircraft operations in the US that are not categorized as commercial operations or military flights. GA aircraft account for almost 97% of the US civil aviation fleet. Unfortunately, GA flights have a much higher fatal accident rate than commercial operations. Recent estimates by the Federal Aviation Administration (FAA) showed that the GA fatal accident rate has remained relatively unchanged between 2010 and 2015, with 1566 fatal accidents accounting for 2650 fatalities. Several research efforts have been directed towards betters understanding the causes of GA accidents. Many of these efforts use National …
Examining Time To Evacuate Dynamically Activated Aircraft Hazard Areas,
2016
The MITRE Corporation
Examining Time To Evacuate Dynamically Activated Aircraft Hazard Areas, Zheng Tao, Granghuai Wang, Ashley G. Williams, Jon L. Semanek, Jonathan L. Schwartz
Space Traffic Management Conference
The growth in launch and reentry operations in the National Airspace System (NAS) presents the Federal Aviation Administration (FAA) with the challenge of integrating them more efficiently while also minimizing effects on other NAS users and maintaining safety. Currently, to maintain safety and account for unforeseen events such as vehicle breakup, the FAA segregates large amounts of airspace, called Aircraft Hazard Areas (AHAs), from traditional NAS users during launch and reentry operations. In order to minimize effects on NAS users, some AHAs during reentry are dynamically activated only if an unexpected event occurs. If a dynamic AHA is activated, then …
Optimization Of A High Power Rocket Vehicle For Autonomous Rover Deployment,
2016
University of Alabama in Huntsville
Optimization Of A High Power Rocket Vehicle For Autonomous Rover Deployment, Davis Hunter, Francis Wessling
Von Braun Symposium Student Posters
No abstract provided.
