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Cfd Study Of Taylor-Like Vortices In Swirling Flows, Sattar Panahandehgar 2019 Embry-Riddle Aeronautical University

Cfd Study Of Taylor-Like Vortices In Swirling Flows, Sattar Panahandehgar

Dissertations and Theses

Swirling flows are complex fluid motions that appear in various natural phenomena and man-made devices. Numerous engineering applications such as turbomachinery, jet engine combustion chambers, mixing tanks and industrial burners involve swirling flows. This wide range of applications is due to unique characteristics offered by swirling flows such as increase in mixing rate, heat transfer rate and wall shear stress. In this study the axisymmetric swirling flow behavior in the context of a hybrid rocket engine have been analyzed. While modeling the flow inside a cylindrical chamber using CFD, a similarity with the Taylor vortices instability has been observed. Similar ...


Low-Tip-Speed High-Torque Proprotor Noise Approximation For Design Cycle Analysis, Xavier G. Santacruz 2019 Embry-Riddle Aeronautical University

Low-Tip-Speed High-Torque Proprotor Noise Approximation For Design Cycle Analysis, Xavier G. Santacruz

Dissertations and Theses

Noise reduction in aviation would enable urban missions that cannot be own with current generation helicopters because of their noisiness. This goal can be achieved by using electric motors as they are quieter and can produce higher torque at lower RPMs. Therefore, a proprotor system can be designed to exploit this characteristic potentially abating noise levels. This research performed noise approximations included with rotor aerodynamics for a single, electric-driven, hovering proprotor by creating a code meant to be used in design cycle analysis. The approximation was based on geometry by using the blade element momentum theory, and calculating the pressure ...


Space Image Processing And Orbit Estimation Using Small Aperture Optical Systems, David Zuehlke 2019 Embry-Riddle Aeronautical University

Space Image Processing And Orbit Estimation Using Small Aperture Optical Systems, David Zuehlke

Dissertations and Theses

Angles-only initial orbit determination (AIOD) methods have been used to find the orbit of satellites since the beginning of the Space Race. Given the ever increasing number of objects in orbit today, the need for accurate space situational awareness (SSA) data has never been greater. Small aperture (< 0:5m) optical systems, increasingly popular in both amateur and professional circles, provide an inexpensive source of such data. However, utilizing these types of systems requires understanding their limits. This research uses a combination of image processing techniques and orbit estimation algorithms to evaluate the limits and improve the resulting orbit solution obtained using small aperture systems. Characterization of noise from physical, electronic, and digital sources leads to a better understanding of reducing noise in the images used to provide the best solution possible. Given multiple measurements, choosing the best images for use is a non-trivial process and often results in trying all combinations. In an effort to help autonomize the process, a novel “observability metric” using only information from the captured images was shown empirically as a method of choosing the best observations. A method of identifying resident space objects (RSOs) in a single image using a gradient based search algorithm was developed and tested on actual space imagery captured with a small aperture optical system. The algorithm was shown to correctly identify candidate RSOs in a variety of observational scenarios.


A Hybrid Vortex Solution For Radial Equilibrium In Axial Compressors, Wenyu Li 2019 Embry-Riddle Aeronautical University

A Hybrid Vortex Solution For Radial Equilibrium In Axial Compressors, Wenyu Li

Dissertations and Theses

A hybrid vortex solution using the radial equilibrium equation for three dimensional design in axial compressors is generated. One of the most common used vortex solutions is Free Vortex. However, it ignores the fact that axial velocity varies with radius. The Hybrid Vortex includes axial velocity distribution with radius, which gives a more effective design. A single stage is first designed using the Free Vortex design method. A low hub-to-tip ratio is set to ensure subsonic flow. The axial velocity profile is exported from the CFX solver of the inlet diffuser. Using the Hybrid Vortex solution to the radial equilibrium ...


Optimal Battery Weight Fraction For Serial Hybrid Propulsion System In Aircraft Design, Tsz Him Yeung 2019 Embry-Riddle Aeronautical University

Optimal Battery Weight Fraction For Serial Hybrid Propulsion System In Aircraft Design, Tsz Him Yeung

Dissertations and Theses

This thesis focuses on electric propulsion technology associated with serial hybrid power plants most commonly associated with urban air mobility vehicles. While closed form analytical solutions for parallel hybrid aviation cases have been determined, optimized serial hybrid power plants have not seen the same degree of fidelity. Presented here are the analytical relationships between several preliminary aircraft design objectives and the battery weight fraction. These design objectives include aircraft weight, range, operation cost, and carbon emissions. The relationships are based on a serial hybrid electric propulsion architecture from an energy standpoint, and can be applied to hybrid aircraft of different ...


Stability Analysis Of A More General Class Of Systems With Delay-Dependent Coefficients, Chi Jin, Keqin Gu, Islam Boussaada, Silviu-Iulian Niculescu 2019 Laboratoire des Signaux et Syst`emes (L2S) CentraleSup´elec-CNRS-Universit´e Paris Sud, 3 rue Joliot- Curie 91192 Gif-sur-Yvette cedex, France.

Stability Analysis Of A More General Class Of Systems With Delay-Dependent Coefficients, Chi Jin, Keqin Gu, Islam Boussaada, Silviu-Iulian Niculescu

SIUE Faculty Research, Scholarship, and Creative Activity

This paper presents a systematic method to analyse the stability of systems with single delay in which the coefficient polynomials of the characteristic equation depend on the delay. Such systems often arise in, for example, life science and engineering systems. A method to analyze such systems was presented by Beretta and Kuang in a 2002 paper, but with some very restrictive assumptions. This work extends their results to the general case with the exception of some degenerate cases. It is found that a much richer behavior is possible when the restrictive assumptions are removed. The interval of interest for the ...


Hybrid Rocket Engine Design Utilizing A Polymer Matrix Encapsulating Pulverized Fuel, Seth Holladay, Teague Aarant, Jared Bass, Timothy Grizzel, Matthew McVey, William Putthoff, Angus Shaw, Caroline Littel, James Evans Lyne 2019 University of Tennessee, Knoxville

Hybrid Rocket Engine Design Utilizing A Polymer Matrix Encapsulating Pulverized Fuel, Seth Holladay, Teague Aarant, Jared Bass, Timothy Grizzel, Matthew Mcvey, William Putthoff, Angus Shaw, Caroline Littel, James Evans Lyne

Chancellor’s Honors Program Projects

No abstract provided.


Design And Development Of Hybrid Rocket For Spaceport America Cup, Benjamin Barnhill, Sean Darling, Austin Springer, Adam Todd, Stewart Whaley 2019 University of Tennessee-Knoxville

Design And Development Of Hybrid Rocket For Spaceport America Cup, Benjamin Barnhill, Sean Darling, Austin Springer, Adam Todd, Stewart Whaley

Chancellor’s Honors Program Projects

No abstract provided.


System Architecture Design And Development For A Reusable Lunar Lander, Chad Batten, Camille E. Bergin, Aaron Crigger, Darryl Harris, Gillian Suzanne McGlothin 2019 University of Tennessee, Knoxville

System Architecture Design And Development For A Reusable Lunar Lander, Chad Batten, Camille E. Bergin, Aaron Crigger, Darryl Harris, Gillian Suzanne Mcglothin

Chancellor’s Honors Program Projects

No abstract provided.


Development Of A One-Equation Turbulence Model Based On K-Ε Closure And Its Extension For Computing Transitional Flows By Including An Intermittency Transport Equation, Cheng Peng 2019 Washington University in St. Louis

Development Of A One-Equation Turbulence Model Based On K-Ε Closure And Its Extension For Computing Transitional Flows By Including An Intermittency Transport Equation, Cheng Peng

Engineering and Applied Science Theses & Dissertations

No abstract provided.


Task 1: Silver-Based Microbial Check Valve For Spacecraft Potable Water Systems, Eric Beitle 2019 University of Arkansas, Fayetteville

Task 1: Silver-Based Microbial Check Valve For Spacecraft Potable Water Systems, Eric Beitle

Chemical Engineering Undergraduate Honors Theses

As human space exploration increases, the development of a more efficient potable water treatment system suited for spacecraft becomes crucial. This Waste-management Education Research Consortium (WERC) challenge was designed to explore the viability of microbial control through the utilization of silver ions as a biocide for possible integration into the Tranquility Node 3 water purification system aboard the International Space Station (ISS). Current systems using iodine risk causing hyperthyroidism from overexposure; however, silver can be safely ingested without this side effect. After researching silver delivery methods including electrochemical ion production, controlled release, or a combination of the two, our team ...


Silver-Based Microbial Check Valve For Spacecraft Potable Water Systems, Rogelio E. Garcia 2019 University of Arkansas, Fayetteville

Silver-Based Microbial Check Valve For Spacecraft Potable Water Systems, Rogelio E. Garcia

Chemical Engineering Undergraduate Honors Theses

As human space exploration increases, the development of a more efficient potable water treatment system suited for spacecraft becomes crucial. This Waste-management Education Research Consortium (WERC) challenge was designed to explore the viability of microbial control through the utilization of silver ions as a biocide for possible integration into the Tranquility Node 3 water purification system aboard the International Space Station (ISS). Current systems using iodine risk causing hyperthyroidism from overexposure; however, silver can be safely ingested without this side effect. After researching silver delivery methods including electrochemical ion production, controlled release, or a combination of the two, our team ...


Hypervelocity Impact Analysis Of Hybrid Nanocomposite Sensors For Inflatable Space Structures, Yachna Gola 2019 Embry-Riddle Aeronautical University

Hypervelocity Impact Analysis Of Hybrid Nanocomposite Sensors For Inflatable Space Structures, Yachna Gola

Dissertations and Theses

Future space exploration requires easy-to-transport, and easy-to-build and deploy space habitats. NASA and Bigelow Aerospace have collaborated so that human habitation can be made safe and easy with inflatable space habitats (Litteken, 2017). One of the biggest threats faced by these structures in outer space is impact damage by micrometeoroid orbital debris (MMOD) traveling at velocities as high as 15 km/s (Lemmens, Krag, Rosebrock, & Carnelli, 2013). This work presents fabrication and testing of hybrid nanocomposites with carbon nanotubes (CNT) and coarse graphene nanoplatelets (GNP) as fillers and flexible epoxy matrix, that are proposed to be used for sensing the ...


Energy Analysis And Orbit Simulation Of Actuating Cubesat Solar Arrays, Justin T. Ehren 2019 University of Dayton

Energy Analysis And Orbit Simulation Of Actuating Cubesat Solar Arrays, Justin T. Ehren

Honors Theses

CubeSats are used in space research to explore new technologies and detect data to gain a better understanding of various areas of research and subjects affecting human life. CubeSats rely on a solar array to generate energy from the sun and perform their various functions in space. This research studies the energy capturing potential of various solar array configurations and positioning devices for CubeSats. The location and orientation of a CubeSat is simulated with MATLAB for both geo-synchronous and sunsynchronous orbits. Two degree-of-freedom (DoF) positioning devices are sufficient to continuously adjust the photovoltaic array to face towards the sun. Lower ...


Investigation Of Thermoplastic Polymers And Their Blends For Use In Hybrid Rocket Combustion, Spencer D. Mathias 2019 Utah State University

Investigation Of Thermoplastic Polymers And Their Blends For Use In Hybrid Rocket Combustion, Spencer D. Mathias

All Graduate Theses and Dissertations

This thesis set out to find a blend of thermoplastics that had better combustion properties than the current ABS (acrylonitrile butadiene styrene) plastic or “Lego TM plastic” used by Utah State University. The current work is in an effort to eliminate toxic propellants from small space applications. High and low density polyethylene plastics were used because they are common plastic waste items. In this way rocket fuel can be made from these items to reduce the waste found in landfills. Three plastics were considered for replacement and as mixture components with the ABS plastic, namely low and high density polyethylene ...


Development And Testing Of Additively Manufactured Aerospike Nozzles For Small Satellite Propulsion, Isaac W. Armstrong 2019 Utah State University

Development And Testing Of Additively Manufactured Aerospike Nozzles For Small Satellite Propulsion, Isaac W. Armstrong

All Graduate Theses and Dissertations

Automatic altitude compensation has been a holy grail of rocket propulsion for decades. Current state-of-the-art bell nozzles see large performance decreases at low altitudes, limiting rocket designs, shrinking payloads, and overall increasing costs. Aerospike nozzles are an old idea from the 1960’s that provide superior altitude-compensating performance and enhanced performance in vacuum, but have survivability issues that have stopped their application in satellite propulsion systems. A growing need for CubeSat propulsion systems provides the impetus to study aerospike nozzles in this application. This study built two aerospike nozzles using modern 3D metal printing techniques to test aerospikes at a ...


Comparison Of Induced And Parasitic Drag On Wings With Minimum Induced Drag, Sarah A. Abdel-Motaleb 2019 Utah State University

Comparison Of Induced And Parasitic Drag On Wings With Minimum Induced Drag, Sarah A. Abdel-Motaleb

All Graduate Plan B and other Reports

Minimizing the induced drag for steady level flight is a variational problem that requires solving for the optimum lift distribution given a set of design constraints. From lifting-line theory, minimizing the induced drag is, in part, achieved by varying the Fourier coefficients used to describe the section lift. The elliptic lift distribution minimizes the induced drag for a wing with fixed weight and wingspan by setting all but the first coefficient to zero. If wingspan is allowed to vary, a negative third Fourier coefficient is utilized to reach an optimum lift distribution that further reduces the induced drag for stress-limited ...


Preliminary Test Predictions For Scale Ram-Air Parachute Testing, Christian A. Guzman Zurita 2019 Embry-Riddle Aeronautical University

Preliminary Test Predictions For Scale Ram-Air Parachute Testing, Christian A. Guzman Zurita

Dissertations and Theses

The present thesis proposes a preliminary analysis to predict the aerodynamic performance for experimental tests of ram-air parachutes in a wind tunnel. A scaled experimental test setup is developed for determining the aerodynamic coefficients of lift (𝐶𝐿) and drag (𝐶𝐷) conducted in a wind tunnel. Additionally, a CFD approach where a steady-state parachute shape defined based on experiments, photographs, and literature, is presented. The accuracy of the simulation depends considerably on the ability to resolve the canopy geometry. Therefore, a CAD geometry generation is implemented for flexible control of the canopy structure by implementing design parameters, e.g., chord, span ...


Reconstruction Of Attenuated Hybrid Rocket Motor Chamber Pressure Signals Using Maximum Likelihood Estimation And Optimal Deconvolution, Evan M. Zelesnik 2019 Utah State University

Reconstruction Of Attenuated Hybrid Rocket Motor Chamber Pressure Signals Using Maximum Likelihood Estimation And Optimal Deconvolution, Evan M. Zelesnik

All Graduate Plan B and other Reports

Chamber pressure, as it develops during rocket combustion, strongly correlates with many of the internal motor ballistics, including combustion stability, fuel regression rate, and mass flow. Chamber pressure is also an essential measurement for calculating achieved thrust coefficient and characteristic velocity. Due to the combustion environment hostility, sensing chamber pressure with high-fidelity presents a difficult measurement problem, especially for solid and hybrid rocket systems where combustion by-products contain high amounts of carbon and other sooty materials. These contaminants tend to deposit within the pneumatic tubing used to transmit pressure oscillations from the thrust chamber to the sensing transducer. Partially clogged ...


Conceptual Design Of A Combat Search And Rescue Surveillance Unmanned Aerial Aircraft, Juan M. Chirinos-Paiz, Keegan J. Musser, Robert M. Zenko, Joshua Hunter 2019 Kennesaw State University

Conceptual Design Of A Combat Search And Rescue Surveillance Unmanned Aerial Aircraft, Juan M. Chirinos-Paiz, Keegan J. Musser, Robert M. Zenko, Joshua Hunter

Senior Design Project For Engineers

Unmanned aerial vehicles (UAV) are becoming more efficient and widely used. The military uses UAV’s because it greatly reduces civilian and combatant deaths and injuries. UAV’s also are used in search and rescue mission to find distress civilians. The team wanted to create an UAV for search and rescue missions and military applications. The aircraft needed to be compact, perform better than other UAV’s, and be low cost. The team did reach a successful aircraft that meet the design requirements. The aircraft was successfully sized around the electronics and allows utilization of additive manufacturing techniques. Project management ...


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