Simulations Of Ion Thruster Plume Contamination With A Whole Grid Sputtered Mo Source Model,
2013
Missouri University of Science and Technology
Simulations Of Ion Thruster Plume Contamination With A Whole Grid Sputtered Mo Source Model, Daoru Frank Han, Joseph J. Wang
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A particle simulation based source model is developed to calculate the density distribution of the sputtered Mo atoms for a whole ion optics grid. The source model is used in PIC simulation of ion thruster plume contamination for 3-grid and 2-grid ion thrusters. The results show that the commonly used point-source approximation for sputtered Mo atoms is oversimplified and would lead to over-prediction of contamination deposition.
The Effects Of Angle-Of-Attack Indication On Aircraft Control In The Event Of An Airspeed Indicator Malfunction,
2013
Embry-Riddle Aeronautical University - Daytona Beach
The Effects Of Angle-Of-Attack Indication On Aircraft Control In The Event Of An Airspeed Indicator Malfunction, Claas Tido Boesser
Doctoral Dissertations and Master's Theses
Analysis of accident data by the Federal Aviation Administration, the National Transportation Safety Board, and other sources show that loss of control is the leading cause of aircraft accidents. Further evaluation of the data indicates that the majority of loss of control accidents are caused by the aircraft stalling. In response to these data, the Federal Aviation Administration and the General Aviation Joint Steering Committee emphasize the importance of stall and angle-of-attack awareness during flight. The high-profile crash of Air France Flight 447, in which pilots failed to recover from a self-induced stall, reinforced concerns over the need for improved …
The Effects Of Sensor Performance As Modeled By Signal Detection Theory On The Performance Of Reinforcement Learning In A Target Acquisition Task,
2013
Embry-Riddle Aeronautical University - Daytona Beach
The Effects Of Sensor Performance As Modeled By Signal Detection Theory On The Performance Of Reinforcement Learning In A Target Acquisition Task, Nate Quirion
Doctoral Dissertations and Master's Theses
Unmanned Aerial Systems (UASs) today are fulfilling more roles than ever before. There is a general push to have these systems feature more advanced autonomous capabilities in the near future. To achieve autonomous behavior requires some unique approaches to control and decision making. More advanced versions of these approaches are able to adapt their own behavior and examine their past experiences to increase their future mission performance. To achieve adaptive behavior and decision making capabilities this study used Reinforcement Learning algorithms. In this research the effects of sensor performance, as modeled through Signal Detection Theory (SDT), on the ability of …
Use Of A Rolling Road System In Crosswind Conditions,
2013
Old Dominion University
Use Of A Rolling Road System In Crosswind Conditions, Mau-Kuo Chen
Mechanical & Aerospace Engineering Theses & Dissertations
Wind tunnel testing continues to play an important role in vehicle aerodynamic development. Accurate results are strongly associated with whether the wind tunnel can closely simulate the on-road conditions, including the Reynolds number and all boundary conditions. Rolling road systems (or moving belts) have been a successful tool for many auto makers and racing teams to simulate the relative motion between the stationary vehicle model and the floor in the test section. The mechanism of the rolling road system is simple, but how it affects the adjacent flow field and how this flow interacts with the flow underneath the vehicle …
Microphone-Based Pressure Diagnostics For Boundary Layer Transition,
2013
California Polytechnic State University, San Luis Obispo
Microphone-Based Pressure Diagnostics For Boundary Layer Transition, Spencer Everett Lillywhite
Master's Theses
An experimental investigation of the use low-cost microphones for unsteady total pressure measurement to detect transition from laminar to turbulent boundary layer flow has been conducted. Two small electret condenser microphones, the Knowles FG-23629 and the FG-23742, were used to measure the pressure fluctuations and considered for possible integration with an autonomous boundary layer measurement system. Procedures to determine the microphones’ maximum sound pressure levels and frequency response using an acoustic source provided by a speaker and a reference microphone. These studies showed that both microphones possess a very flat frequency response and that the max SPL of the FG-23629 …
Improving Affordability: Separating Research From Development And From Design In Complex Programs,
2013
Loyola Marymount University
Improving Affordability: Separating Research From Development And From Design In Complex Programs, Bohdan W. Oppenheim
Systems Engineering Faculty Works
This paper presents arguments for why defense programs creating physical systems should clearly separate three developmental phases from each other: research, development and design. Research is to be performed first by small teams of scientists addressing the "unknown unknowns" and maturing fundamental science from TRL of 1 to about 3. Next, development of physical modules is to be performed by small and highly specialized engineers. Finally, the system-level design should focus on efficient trading off the module locations, sizes and shapes versus system performance, mass, power requirements, etc. The design with all modules mature and available is equivalent to a …
Creating Exact Bezier Representations Of Cst Shapes,
2013
California Polytechnic State University - San Luis Obispo
Creating Exact Bezier Representations Of Cst Shapes, David D. Marshall
Aerospace Engineering
The paper presents a method of expressing CST shapes pioneered by Kulfan into standard Bezier curves and surfaces. Out of the seven standard shape classes identified by Kulfan as representable using CST curves, four of them, including airfoils, can be represented as Bezier curves exactly. For the other three, a convergent series expansion proves insufficient to achieve any practical accuracy, however these three classes are not the most commonly used of the CST classes. With the ability to express most common CST curves and surfaces as generic Bezier curves and surfaces, CST shapes can be used in CAD, solid modeling, …
Design Of A Lighter Than Air Vehicle That Achieves Positive Buoyancy In Air Using A Vacuum,
2013
Air Force Institute of Technology
Design Of A Lighter Than Air Vehicle That Achieves Positive Buoyancy In Air Using A Vacuum, Trent T. Metlen
Theses and Dissertations
Three designs for a Lighter Than Air (LTA) structure that achieve positive buoyancy using a vacuum in place of a lifting gas were proposed and evaluated. The ratio of structure weight to the weight of displaced air was termed Weight/Buoyant Force (W/B) where a W/B1 corresponds to positive buoyancy. Two methods of geometrically stiffening a sphere were investigated and their W/B evaluated. A thin shelled sphere of beryllium stiffened with an isogrid of blade type stiffeners using Ultra High Modulus (UHM) carbon epoxy was predicted to give a W/B= 0.79. A geodesic sphere composed of a frame of cylindrical, UHM, …
Crack Initiation And Growth Behavior At Corrosion Pit In 7075-T6 High Strength Aluminum Alloy,
2013
Air Force Institute of Technology
Crack Initiation And Growth Behavior At Corrosion Pit In 7075-T6 High Strength Aluminum Alloy, Eric M. Hunt
Theses and Dissertations
Research on fatigue crack formation from two types corrosion pits tangent to a circular hole in a 7075-T6 aluminum alloy subjected to uni-axial loads (R = 0.5, lambda = 0) in both an air and saltwater environment provides a method for exploring crack initiation and initial growth rates. This work focuses on a fracture mechanics approach to explore the transition from corrosion pit to crack growth. Specimens with a cylinder shaped through-pit tangent to a circular hole have a closed form solution to predict this delta K that closely resembles the finite element solutions. Specimens with a semi-circular corner-pit tangent …
Kysat-2 Electrical Power System Design And Analysis,
2013
Morehead State University
Kysat-2 Electrical Power System Design And Analysis, Brandon L. Molton
Morehead State Theses and Dissertations
A Thesis Presented to the Faculty of the College of Science & Technology Morehead State University in Partial Fulfillment of the Requirements for the Degree Master of Science by Brandon L. Molton on June 4, 2013.
Control System Infrastructure For The Cal Poly Human Powered Helicopter: Upturn Ii,
2013
California Polytechnic State University, San Luis Obispo
Control System Infrastructure For The Cal Poly Human Powered Helicopter: Upturn Ii, Douglas A. Thornber, Samuel J. Wahyou
Aerospace Engineering
The Upturn was donated to Cal Poly in October 2012 by Neal Saiki from NTS. Our project was to replicate the old system to decrease the turn-around time in case of a crash during a test flight. The control system for the Upturn II was designed with the same considerations that were used for the Upturn. The result we got was inconclusive for the sensor selection, the new control system is heavier than the old system, and we couldn’t validate the system without doing a flight test. For the next iteration if some of the replication requirements are relaxed the …
Incorporating Aluminum Honeycomb To Increase Efficiency Of U-Tube Removable Heat Exchanger,
2013
California Polytechnic State University, San Luis Obispo
Incorporating Aluminum Honeycomb To Increase Efficiency Of U-Tube Removable Heat Exchanger, Daniel Soto, Daniel Corona
Aerospace Engineering
This report contains the results of attempting to improve on the results of Scott R. Sawyer and Alan M. L’Esperance research paper “Investigation of Paraffin Wax as an Energy Storage Medium Within a Shell-and-Tube Heat Exchanger.” The overall goal of the paper mentioned was to investigate the usefulness of wax as an energy storage medium. Scott R. Sawyer and Alan M. L’Esperance determined that “the amount of energy that can be released by the paraffin wax back to the airflow reaches a plateau, despite an increase in heating times.” They suggested that by surrounding the airflow tubes of a heat …
Fin Flutter Analysis,
2013
California Polytechnic State University, San Luis Obispo
Fin Flutter Analysis, Richard Bauer, Austin Hardman
Aerospace Engineering
This report summarizes the experimental process executed to study fin flutter characteristics. The experiment analyzed the influence of the relationship between structural dynamics and aerodynamics on flutter characteristics. Theoretical models were created in PATRAN/NASTRAN and FinSim for comparison to experimental results and to set the envelope of the physical experiments. The theoretical analysis predicted the occurrence of flutter near Mach 1 or Mach 5. The physical model was constructed of solid aluminum with machined holes for the inertial sensors. Two test runs were completed to collect data on the displacement of the fin in the supersonic wind tunnel. Additionally, the …
Creation And Analysis Of An Electric And Magnetic Model Of A Micro Ion Thruster,
2013
California Polytechnic State University, San Luis Obispo
Creation And Analysis Of An Electric And Magnetic Model Of A Micro Ion Thruster, Maxwell Bodnar
Aerospace Engineering
This report explores the magnetic and electric fields within the Cal Poly Miniature Xenon Ion (MiXI) Thruster V3 in order to create a comprehensive electric and magnetic model of the plasma chamber to analyze and test the current thruster configurations and changes to the existing thruster. This model is used to analyze the operation and efficiency of the ion thruster and the plasma environment within the plasma chamber. This model explores the ionization and electron collision rates during operation of the thruster to measure the efficiency of the current thruster configuration, also determining the theoretical Isp and thrust of the …
Low-Cost Imu Implementation Via Sensor Fusion Algorithms In The Arduino Environment,
2013
California Polytechnic State University, San Luis Obispo
Low-Cost Imu Implementation Via Sensor Fusion Algorithms In The Arduino Environment, Brandon Mccarron
Aerospace Engineering
A multi-phase experiment was conducted at Cal Poly in San Luis Obispo, CA, to design a low-cost inertial measurement unit composed of a 3-axis accelerometer and 3-axis gyroscope. Utilizing the growing microprocessor software environment, a 3-axis accelerometer and 3-axis gyroscope simulated 6 degrees of freedom orientation sensing through sensor fusion. By analyzing a simple complimentary filter and a more complex Kalman filter, the outputs of each sensor were combined and took advantage of the benefits of both sensors to improved results. Gyroscopic drift was removed in the pitch and roll axes using the Kalman filter for both static and dynamic …
Ramjet Combustion Chamber,
2013
California Polytechnic State University, San Luis Obispo
Ramjet Combustion Chamber, Paul Cameron Stone
Aerospace Engineering
A ramjet combustion chamber is designed and some initial assembly fabrication and test completed as a component of a ramjet graduate project for California Polytechnic State University, San Luis Obispo Supersonic Wind Tunnel. The combustor design is driven by a theoretical model created by a Cal Poly graduate student, Harrison Sykes. Temperature, pressure, and fuel flow will be measured.
Paschen Breakdown In A Co2 Atmosphere,
2013
California Polytechnic State University, San Luis Obispo
Paschen Breakdown In A Co2 Atmosphere, Matthew T. Stumbo
Aerospace Engineering
This report observes and analyzes the effect the pressure and gap distance have on the minimum positive breakdown potential between two parallel plate copper electrodes in both air and CO2. Two gap distances, 0.57 cm and 2.44 cm, were used. Paschen Curves generated in air from these distances had a strong positive correlation with a Spearman correlation coefficient of 0.97. Curves generated in CO2 had a Spearman correlation coefficient of 0.87. The strong correlation for both gases verifies Paschen's Law. The minimum breakdown potential in air was 361 ± 2 V at a pressure x gap distance …
The Effects Of Fabrication Methods And Cure Cycle On The Mechanical Properties Of Carbon Fiber Laminate In Tensile And 3-Point Bend Testing,
2013
California Polytechnic State University, San Luis Obispo
The Effects Of Fabrication Methods And Cure Cycle On The Mechanical Properties Of Carbon Fiber Laminate In Tensile And 3-Point Bend Testing, Adriano Agostino
Aerospace Engineering
This project was completed at the California Polytechnic State University, San Luis Obispo Aerospace Engineering Structures and Composites Lab during Spring Quarter 2013. The purpose of this project was to research and to gain insight into the effects of fabrication methods and of modifying cure cycles for Newport NB-301 12l 2x2 Twill Weave Carbon Fiber material properties. The two fabrication methods used were autoclave and heat press (compression molding) methods. Each fabrication method used two cure cycles, a recommended cure cycle of 275°F for 1 hour and a modified cure cycle of 250°F for 1.5 hours. The exact product data …
Study Of Natural Composite Materials Square Beam Under Three Point Bending Test,
2013
California Polytechnic State University, San Luis Obispo
Study Of Natural Composite Materials Square Beam Under Three Point Bending Test, Casey Wu
Aerospace Engineering
The purpose of this report is to summarize the findings on three point bending tests to try to find the optimum geometrical shape and layup configuration of a square beam composed of natural composites. The final project was entered into the SAMPE 2013 bridge building competition to compete internationally against other universities in the natural square beam category. The main focus of the bridge project is to compose it entirely of natural occurring fibers and other natural materials to create a “green” beam. The beams in the competition are tested under 3 point bending tests and will be scored based …
Design And Fabrication Of A Ramjet Engine,
2013
California Polytechnic State University, San Luis Obispo
Design And Fabrication Of A Ramjet Engine, Clinton C. Humphrey
Aerospace Engineering
In this report, the design and fabrication of the inlet to a ramjet engine is described. The inlet utilizes a single ramp and single sided three shock internal compression to slow the airflow from supersonic to subsonic speeds while providing maximum stagnation pressure to the combustor. The optimum angle for the inlet ramp is calculated to be 10° and it decelerates the airflow from Mach 3.3019 to Mach 0.5438. The stagnation pressure increases from 150 psi to 4.67 ksi. The material of the inlet is composed primarily of low carbon mild steel to accommodate the high pressure of the inlet.
