Wind Tunnel Modeling Of Small Electric Uav Power System Performance,
2011
California Polytechnic State University, San Luis Obispo
Wind Tunnel Modeling Of Small Electric Uav Power System Performance, Nathan R. Phelps
Aerospace Engineering
This report details the design and construction of a testing apparatus for characterization of small electric aircraft power systems designed for use in the California Polytechnic State University San Luis Obispo Aerospace Engineering department’s subsonic wind tunnel. This apparatus was constructed and implemented with the goal of determining system and component efficiencies of an entire power system using RC Aircraft components as an analog for systems currently in use in the current generation of small electric UAV’s in service with the US Armed Forces. The goal of these experiments was to determine where improvements in the system architecture can be …
Radiation In The Space Environment,
2011
California Polytechnic State University, San Luis Obispo
Radiation In The Space Environment, Sally Hermansen, Jennifer Shatts
Aerospace Engineering
No abstract provided.
Global Optimization Of Mga-Dsm Problems Using The Interplanetary Gravity Assist Trajectory Optimizer (Igato),
2011
California Polytechnic State University, San Luis Obispo
Global Optimization Of Mga-Dsm Problems Using The Interplanetary Gravity Assist Trajectory Optimizer (Igato), Jason M. Bryan
Master's Theses
Interplanetary multiple gravity assist (MGA) trajectory optimization has long been a field of interest to space scientists and engineers. Gravity assist maneuvers alter a spacecraft's velocity vector and potentially allow spacecraft to achieve changes in velocity which would otherwise be unfeasible given our current technological limitations. Unfortunately, designing MGA trajectories is difficult and in order to find good solutions, deep space maneuvers (DSM) are often required which further increase the complexity of the problem. In addition, despite the active research in the field over the last 50 years, software for MGA trajectory optimization is scarce. A few good commercial, and …
Experimental Investigation Of A 2-D Air Augmented Rocket: Effects Of Nozzle Lip Thickness On Rocket Mixing And Entrainment,
2011
California Polytechnic State University, San Luis Obispo
Experimental Investigation Of A 2-D Air Augmented Rocket: Effects Of Nozzle Lip Thickness On Rocket Mixing And Entrainment, Trevor Allen Montre
Master's Theses
Cold-flow tests were performed using a simulated Air Augmented Rocket (AAR) operating as a mixer-ejector in order to investigate the effects of varied primary nozzle lip thickness on mixing and entrainment. The simulated primary rocket ejector was supplied with nitrogen at a maximum chamber stagnation pressure of 1712 psi, and maximum flow rate of 1.67 lbm/s. Secondary air was entrained from a plenum, producing pressures as low as 6.8 psi and yielding maximum stagnation pressure ratios as high as 160. The primary ejector nozzles each had an area ratio of approximately 20, yielding average primary exit Mach numbers …
Vortex Tilting And The Enhancement Of Spanwise Flow In Flapping Wing Flight,
2011
University of Central Florida
Vortex Tilting And The Enhancement Of Spanwise Flow In Flapping Wing Flight, Spencer Frank
HIM 1990-2015
In summary the tilting mechanism helps to explain the overall flow structure and the stability of the leading edge vortex.; The leading edge vortex has been identified as the most critical flow structure for producing lift in flapping wing flight. Its stability depends on the transport of the entrained vorticity into the wake via spanwise flow. This study proposes a hypothesis for the generation and enhancement of spanwise flow based on the chordwise vorticity that results from the tilting of the leading edge vortex and trailing edge vortex. We investigate this phenomenon using dynamically scaled robotic model wings. Two different …
Aircraft Longitudinal Control Experiment,
2011
California Polytechnic State University, San Luis Obispo
Aircraft Longitudinal Control Experiment, Dustin Schaff
Aerospace Engineering
This paper describes the design, fabrication, and analysis of an experiment that demonstrates the stability and control system characteristics of an aircraft constrained at the center of gravity in an air flow field. Given a set of basic requirements, the physical system (including the airframe, wings, tail, and mounted ball bearing) was designed, modeled, and manufactured. With the aircraft placed in front of a fan and allowed to rotate freely with the ball bearing, an angular rate sensor and servo motor to the deflect the elevator may be connected to any computer using an analog/digital Data Acquisition (DAQ) device to …
Cubesat Constellation Analysis For Data Relaying,
2011
California Polytechnic State University, San Luis Obispo
Cubesat Constellation Analysis For Data Relaying, Bradley Ryan Smalarz
Master's Theses
Current CubeSat communication technology limits the amount of time, and number of accesses with ground stations. It has been proposed to use a constellation of CubeSats to improve relay performance and increase the number of accesses between a CubeSat and ground stations. By using the spatial and temporal analysis features of STK, coupled with the STK/Matlab interface a robust tool was created to analyze the performance of CubeSat constellations based on a store-and-forward communications model which is not currently supported by the STK Engine. Utilizing the Connect messaging format through a socket connection on the local machine, a Matlab graphical …
Comet: Constrained Optimization Of Multiple-Dimensions For Efficient Trajectories,
2011
California Polytechnic State University, San Luis Obispo
Comet: Constrained Optimization Of Multiple-Dimensions For Efficient Trajectories, Michael Curt Conrad
Master's Theses
The paper describes the background and concepts behind a master’s thesis platform known as COMET (Constrained Optimization of Multiple-dimensions for Efficient Trajectories) created for mission designers to determine and evaluate suitable interplanetary trajectories. This includes an examination of the improvements to the global optimization algorithm, Differential Evolution, through a cascading search space pruning method and decomposition of optimization parameters. Results are compared to those produced by the European Space Agency’s Advanced Concept Team’s Multiple Gravity Assist Program. It was found that while discrepancies in the calculation of ΔV’s for flyby maneuvers exist between the two programs, COMET showed a noticeable …
Analysis Of Leo Radiation Environment And Its Effects On Spacecraft's Critical Electronic Devices,
2011
Embry-Riddle Aeronautical University
Analysis Of Leo Radiation Environment And Its Effects On Spacecraft's Critical Electronic Devices, Luz Maria Martines Sierra
Doctoral Dissertations and Master's Theses
Spacecraft, space stations, satellites and astronauts are exposed to an increased level of radiation when in space, and it is important to evaluate the risks associated with extended radiation exposures in missions and space travel in general. The thesis focuses on the LEO radiation environment and how the particles in it interact with materials. Using existing empirical models, the exposed dosage due to the LEO space environment radiation sources, as a function of orbital altitude, orbital inclination and duration is studied. The physical processes that can result in failures and long term degradations of electronic devices due to solar radiation, …
Improving The Efficiency Of Lpg Compression Ignition Engines For Passenger Cars Through Waste Heat Recovery,
2011
Missouri University of Science and Technology
Improving The Efficiency Of Lpg Compression Ignition Engines For Passenger Cars Through Waste Heat Recovery, Alberto Boretti
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The turbocharged direct injection lean burn Diesel engine is the most efficient now in production for transport applications with full load brake efficiencies up to 40 to 45% and reduced penalties in brake efficiencies reducing the load by the quantity of fuel injected. the secrets of this engine's performances are the high compression ratio and the lean bulk combustion mostly diffusion controlled in addition to the partial recovery of the exhaust energy to boost the charging efficiency. the major downfalls of this engine are the carbon dioxide emissions and the depletion of fossil fuels using fossil diesel, the energy security …
Efficient Uncertainty Quantification In Multidisciplinary Analysis Of A Reusable Launch Vehicle,
2011
Missouri University of Science and Technology
Efficient Uncertainty Quantification In Multidisciplinary Analysis Of A Reusable Launch Vehicle, Benjamin R. Bettis, Serhat Hosder, Tyler Winter
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The objective of this study was to apply a recently developed uncertainty quantification framework to the multidisciplinary analysis of a reusable launch vehicle (RLV). This particular framework is capable of efficiently propagating mixed (inherent and epistemic) uncertainties through complex simulation codes. the goal of the analysis was to quantify uncertainty in various output parameters obtained from the RLV analysis, including the maximum dynamic pressure, cross-range, range, and vehicle takeoff gross weight. Three main uncertainty sources were treated in the simulations: (1) reentry angle of attack (inherent uncertainty), (2) altitude of the initial reentry point (inherent uncertainty), and (3) the Young's …
Alternative Crankshaft Mechanisms And Kinetic Energy Recovery Systems For Improved Fuel Economy Of Light Duty Vehicles,
2011
Missouri University of Science and Technology
Alternative Crankshaft Mechanisms And Kinetic Energy Recovery Systems For Improved Fuel Economy Of Light Duty Vehicles, Alberto Boretti, Houshsng Masudi, Joseph Scalzo
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The introduction of advanced internal combustion engine mechanisms and powertrains may improve the fuel conversion efficiency of an engine and thus reduce the amount of energy needed to power the vehicle. the paper presents a novel design of a variable compression ratio advanced spark ignition engine that also permits an expansion ratio that may differ from the induction stroke therefore generating an Atkinson cycle effect. the stroke ratio and the ratio of maximum to minimum in-cylinder volumes may change with load and speed to provide the best fuel conversion efficiency. the variable ratio of maximum to minimum in-cylinder volumes also …
Nonlinear Aerodynamic Corrections To Blade Element Momentum Model With Validation Experiments,
2011
Utah State University
Nonlinear Aerodynamic Corrections To Blade Element Momentum Model With Validation Experiments, Robert S. Merrill
All Graduate Plan B and other Reports, Spring 1920 to Spring 2023
Blade element momentum theory is well suited for propeller analysis during the early stages of design. The analytic blade element momentum model is presented along with a proposed nonlinear improvement. The analytical model makes small angle assumptions which are known to be inaccurate under some conditions. The nonlinear model avoids these assumptions. The results of the analytical and nonlinear models are compared against each other. The differences between these are most prevalent on lower pitch propellers at high advance ratios. A wind tunnel validation test is outlined. Results of the validation test and other published data from the University of …
Engineering Model To Calculate Mass Flow Rate Of A Two-Phase Saturated Fluid Through An Injector Orifice,
2011
Utah State University
Engineering Model To Calculate Mass Flow Rate Of A Two-Phase Saturated Fluid Through An Injector Orifice, Brian J. Solomon
All Graduate Plan B and other Reports, Spring 1920 to Spring 2023
An engineering model is developed to calculate mass flow rate of nitrous oxide, a self-pressurizing saturated oxidizer commonly used in hybrid rocket motors. While use of N_{2}0 cannot be accurately modeled using traditional ideal gas, compressible, or incompressible flow assumptions. To obtain accurate mass flow rate this one-dimensional analysis includes both incompressible fluid and homogeneous equilibrium mass flow rate models. Mass flow calculations from the two models are independently weighted and summed to obtain representative two-phase mass flow rate. Fluid properties are iterated in time by keeping track of fluid enthalpy and are propagated across the injector using either isentropic …
Optimization Of A Low Reynold's Number 2-D Inflatable Airfoil Section,
2011
Utah State University
Optimization Of A Low Reynold's Number 2-D Inflatable Airfoil Section, Todd A. Johansen
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A stand-alone genetic algorithm (GA) and an surrogate-based optimization (SBO) combined with a GA were compared for accuracy and performance. Comparisons took place using the Ackley Function and Rastrigin's Function, two functions with multiple local maxima and minima that could cause problems for more traditional optimization methods, such as a gradient-based method. The GA and SBO with GA were applied to the functions through a fortran interface and it was found that the SBO could use the same number of function evaluations as the GA and achieve at least 5 orders of magnitude greater accuracy through the use of surrogate …
Radiative And Nonradiative Decay Rates In Chromium-Related Centers In Nanodiamonds,
2011
Missouri University of Science and Technology
Radiative And Nonradiative Decay Rates In Chromium-Related Centers In Nanodiamonds, S. Castelletto, Alberto Boretti
Mechanical and Aerospace Engineering Faculty Research & Creative Works
We address for the first time the measurement of nonradiative decay rates in Cr-related centers in nanodiamonds. Compared to our previous quantum efficiency measurement of Cr centers created in bulk diamond, separate measurements of radiative and nonradiative decay rates in grown nanodiamonds prove more challenging due to size dependence effects. We demonstrate in this Letter that, using defocused dipole imaging and collection efficiency calculation via finite-difference time-domain (FDTD), a quantum efficiency up to 0.9 can be inferred to Cr-related centers showing a 2-level system photon statistics. © 2011 Optical Society of America.
Formulation Of An Optimal Search Strategy For Space Debris At Geo,
2011
California Polytechnic State University, San Luis Obispo
Formulation Of An Optimal Search Strategy For Space Debris At Geo, Daniel J. Jackson
Master's Theses
The purpose of this thesis is to create a search strategy to find orbital debris when the object fails to appear in the sky at its predicted location. This project is for NASA Johnson Space Center Orbital Debris Program Office through the MODEST (Michigan Orbital Debris Survey Telescope) program. This thesis will build upon the research already done by James Biehl in “Formulation of a Search Strategy for Space Debris at GEO.” MODEST tracks objects at a specific right ascension and declination. A circular orbit assumption is then used to predict the location of the object at a later time. …
Implementation And Validation Of The Ζ-F And Asbm Turbulence Models,
2011
California Polytechnic State University, San Luis Obispo
Implementation And Validation Of The Ζ-F And Asbm Turbulence Models, Dustin Van Blaricom Quint
Master's Theses
The use of Computational Fluid Dynamics (CFD) tools throughout the engineering industry has become standard. Simulations are used during nearly all steps throughout the life cycle of products including design, production, and testing. Due to their wide range of use, industrial CFD codes are becoming more flexible and easier to use. These commercial codes require robustness, reliability, and efficiency. Consequently, linear eddy viscosity models (LEVM) are used to model turbulence for an increasing number of flow types. LEVM such as k-ε and k-ω provide modeling with little loss of computational efficiency and have proven to be robust. The LEVM that …
Diesel-Like And Hcci-Like Operation Of A Truck Engine Converted To Hydrogen,
2011
Missouri University of Science and Technology
Diesel-Like And Hcci-Like Operation Of A Truck Engine Converted To Hydrogen, Alberto A. Boretti
Mechanical and Aerospace Engineering Faculty Research & Creative Works
In addition to the traditional spark ignition (SI), premixed, gasoline-like and compression ignition (CI), diffusion, Diesel-like operation of internal combustion engines, premixed, homogeneous charge, compression ignition (HCCI) operation has also been proposed to improve the fuel conversion efficiency and reduce the pollutant formation. to be attractive, the operation in HCCI mode has to be coupled with the other traditional operations, being HCCI in general difficult to be controlled and limited to values of the air-to-fuel equivalence ratio λ within a narrow windows set by the lean burn limits with large λ and the peak pressure limits with small λ. Furthermore, …
A Look At Near-Term Nuclear Fission And Fusion Rockets For Human Mars Missions,
2011
University of Alabama in Huntsville
A Look At Near-Term Nuclear Fission And Fusion Rockets For Human Mars Missions, Douglass W. Casey
Von Braun Symposium Student Posters
No abstract provided.
