Radiation In The Space Environment, Sally Hermansen, Jennifer Shatts

Aerospace Engineering

No abstract provided.

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 …

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 …

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 …

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 lb_m/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 …

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 …

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 …

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 …

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. …

Performance Analysis Of A Variable Conductance Heat Pipe, Herron Arreola

Aerospace Engineering

This report examines the analysis of a donated Boeing variable conductance heat pipe with unknown performance characteristics. These characteristics were found through experimental means by utilizing 14 thermocouples attached to various locations on the heat pipe, the heaters and to the insulation. Although the maximum axial heat transport capability could not be determined due to the limited number of strip heaters available, the maximum radial heat flux capability of the heat pipe was found to be 2.46 W/in². The experiment also revealed that increasing the input power decreased the burn out inclination angle and that using a coolant …

Constrained Hermite Tls For Mesh-Free Derivative Estimation Near And On Boundaries, Robert A. Mcdonald, Alejandro Ramos

Aerospace Engineering

A Taylor series least-squares approach to estimating derivatives on scattered data is extended to include derivative observation or specification. This approach allows improved estimation of derivatives near boundaries as compared with the standard ghost node approach. It also enables a unique method of estimating derivatives in a surface using only surface data.

Considerations For Numerical Modeling Of Inverted Wings In Ground Effects, Graham Doig, Tracie J. Barber

Aerospace Engineering

No abstract provided.

An Automated Test Station Design Used To Verify Aircraft Communication Protocols, Joshua Berrian

Master's Theses

Requirements verification is typically the costliest part of the systems engineering design process. In the commercial aircraft industry, as the software and hardware design evolves, it must be verified to conform to requirements. In addition, when new design releases are made, regression analysis must be performed which usually requires repeat testing. To streamline verification, a suite of automated verification tools is described in this document which can reduce the test effort. This test suite can be qualified to be used to verify systems at any DO-178B design assurance level. Some of the software tools are briefly described below.

There are …

Flow Characteristics Of The Renovated Cal Poly 3 X 4 Ft Subsonic Wind Tunnel, Mathew L. Thomas, Dorian V. Pandey, Jason N. Nguyen

Aerospace Engineering

This paper investigates the flow characteristics of the renovated Cal Poly 3 x 4 ft subsonic wind tunnel. The IFA 300 constant-temperature anemometer along with a cross-plane X-wire dual-sensor probe was used to measure the mean velocity and turbulence intensity of the tunnel flow and part of the turbulent boundary layer at one section of the tunnel. Because of the malfunction of one channel of the IFA 300, only one wire of the dual sensor probe was calibrated for the measurements. The probe was then placed in a streamlined probe holder mounting on the traverse inside the wind tunnel. The …

Mission Performance Considered As Point Performance In Aircraft Design, Robert A. Mcdonald

Aerospace Engineering

The cruise or loiter performance of an aircraft is intimately tied to its wing loading and its thrust-to-weight ratio. Paradoxically, mission performance is often not considered when these fundamental aircraft parameters are determined in conceptual design. In this paper, the traditional constraint diagram is extended to include contours of range or endurance parameter. These performance metrics represent the mission-performance capability of the aircraft without sizing the aircraft to a particular mission. This gives the designer an immediate and intuitive understanding of the tradeoff between the point and mission performance of the aircraft. The potential freedom for the designer to choose …

Vibration-Based Health Monitoring Of Multiple-Stage Gear Train And Differential Planetary Transmission Involving Teeth Damage And Backlash Nonlinearity, Andrew Patrick Sommer

Master's Theses

The objective of this thesis is to develop vibration-based fault detection strategies for on-line condition monitoring of gear transmission systems. The study divides the thesis into three sections. First of all, the local stresses created by a root fatigue crack on a pinion spur gear are analyzed using a quasi-static finite element model and non-linear contact mechanics simulation. Backlash between gear teeth which is essential to provide better lubrication on tooth surfaces and to eliminate interference is included as a defect and a necessary part of transmission design. The second section is dedicated to fixed axis power trains. Torsional vibration …

Sitting In The Pilot's Seat: Optimizing Human-Systems Interfaces For Unmanned Aerial Vehicles, Steven Michael Queen, Kurt Sanner

STAR Program Research Presentations

One of the pilot-machine interfaces (the forward viewing camera display) for an Unmanned Aerial Vehicle called the DROID (Dryden Remotely Operated Integrated Drone) will be analyzed for optimization. The goal is to create a visual display for the pilot that as closely resembles an out-the-window view as possible. There are currently no standard guidlines for designing pilot-machine interfaces for UAVs. Typically, UAV camera views have a narrow field, which limits the situational awareness (SA) of the pilot. Also, at this time, pilot-UAV interfaces often use displays that have a diagonal length of about 20". Using a small display may result …

Simulation Of Wing Tip Vortices, Ryan Termath, Jason Lechniak, Keerti Bhamidipati

STAR Program Research Presentations

Modeling and Simulation (M&S) computational fluid dynamics (CFD) techniques were used to better understand wing tip vortices about a wing section. The CFD results were compared to experimental wind tunnel data derived from the University of Iowa (Ref. 2). The experiment used Stereoscopic Particle Image Velocimetry (SPIV) to measure the flow field. The SPIV data from the experiment illustrates the vortex core development and behavior downstream of the trailing edge of the wing section. Three CFD simulations using various mesh sizes and time steps were completed and compared to the experimental results. Two dimensional plots of modeled local flow field …

Unsteady Total Pressure Measurement For Laminar-To-Turbulent Transition Detection, Akane Sharon Karasawa

Master's Theses

This thesis presents the use of an unsteady total pressure measurement to detect laminar-to-turbulent transition. A miniature dynamic pressure transducer, Kulite model XCS-062-5D, was utilized to measure the total pressure fluctuations, and was integrated with an autonomous boundary layer measurement device that can withstand flight test conditions. Various sensor-probe configurations of the Kulite pressure transducer were first examined in a wind tunnel with a 0.610 m (2.0 ft) square test section with a maximum operational velocity of 49.2 m/s (110 mph), corresponding dynamic pressure of 1.44 kPa (30 psf). The Kulite sensor was placed on an elliptical nose flat plate …

Analysis And Design Of A Propulsion System Trade Study Tool For A Boeing 376 Series Communications Satellite, Kevin Dunk

Aerospace Engineering

No abstract provided.

3d Cfd On An Open Wheel Race Car Front Wing In Ground Effects, Thomas A. Price

Aerospace Engineering

The purpose of the report is to investigate the ability of the Fluent 6.3 k-ε Realizable turbulence model with standard wall functions to model the flow around the front wing of Cal Poly’s 2008 Formula SAE car. The three primary areas of interest are ground effects, the wing wheel interaction, and the wing tip vortices. Fluent was successful at modeling the increase suction from the ground effects, and the upwash due to the wing tip vortices. The results also displayed how the high pressure region in front of the tire propagates forward and interacts with the pressure distribution around the …

Comparison Of A High Purity Germanium Gamma Ray Spectrometer And A Multidimensional Nai(T1) Scintillation Gamma Ray Spectrometer, Greg Stratton

Aerospace Engineering

This report compares two different gamma ray spectrometers in terms of performance, operation, and apparatus and also investigates the design and integration challenges of using gamma ray spectrometers in space. The first spectrometer is a one-dimensional high purity germanium (HPGe) spectrometer and the second is a multidimensional NaI(Tl) scintillation spectrometer (MGRS). The key results show that the HPGe exhibits 15 to 27 times better energy resolution than the MGRS, but the MGRS is 52 times more sensitive and removes 177 % more of the background radiation.

The Effects Of Damage Arrestment Devices In Composite Plate Sandwiches With Fastener Holes, Mark Anderson, Nancy Hung Choy, Lacey Jones, Rita Kourskaya

Aerospace Engineering

Composite materials such as a carbon fiber are used in a variety of new technologies including aircraft, spacecraft, and motor vehicles. Carbon fiber has a high strength to weight ratio, a key advantage over other material options. This report discusses the use of composite damage arrestment devices (DADs) in composite sandwich panels with a foam core. There are three different curing cycles tested for the DADs: pressure only, vacuum only, and vacuum with 1000 lbs of pressure. Using a Tetrahedron Heat Press to cure the composite specimen and an Instron Machine to perform tensile testing, data was collected for each …

Composite I-Beam Fabrication And Testing In Response To 14th Annual Sampe Bridge Competition, Kodi Rider, Niño Noel Las Piñas, Hans Mayta

Aerospace Engineering

Composites are a type of material that generally combines two materials yielding mechanical properties that are different than its constituent parts. These constituents are classified as either a fiber or a matrix. The objective of this project is to create a carbon-fiber composite I-beam that meets the specifications of the SAMPE student bridge competition. The I-beam consists of carbon fiber unidirectional and woven laminas, as well as aluminum honeycomb and high density polystyrene foam to stiffen the structure. The bridge contest rules limit the dimensions and weight of the bridge. The cross-section must be within 4 inches x 4 inches …

Thermal Analysis Of The Cubesat Cp3 Satellite, Jonas Friedel, Sean Mckibbon

Aerospace Engineering

Due to inconsistencies found in the on-orbit thermal data from the CubeSat CP3 satellite between 2007 and 2011, further analysis is performed on a larger number of data from August 2010 through April 2011, aiming to find an explanation for the overall increasing measured temperatures and shortening peak periods. Therefore, the satellite power data as well as orbital anomalies are analyzed leading to the conclusion that the satellite was temporarily (January – March 2011) orbiting with significantly increased sun exposure causing the higher temperatures. The shortened temperature peak periods are explained by alternating albedo values as the main influence in …

Determination Of The Surface Boundary Layer Using A Quadrotor, Andrew Haviland

Aerospace Engineering

Wind velocity data was taken by a quadrotor UAV using accelerometers, gyroscope, and a barometer. Data was taken at different altitudes over a single position to determine the boundary layer at the surface of the earth. The data taken was compared to the results from numerical methods to determine if this is a practice application for a quadrotor. A few weeks before the test was set to get underway, the quadrotor suffered a very hard crash while testing the GPS and altitude hold function and wasn’t able to completely recover from it. Theoretical results and experiment proposal are covered.

Flexi-Focus Lens: Pdms Variable Focal Length Lens, Patrick Angulo, Alex Doyle, Dylan Mcdaniel, Michael Olivarez

Industrial and Manufacturing Engineering

The design of a variable focal length, or flexi-focus, polydimethylsiloxane (PDMS) lens incorporating a light emitting diode (LED) source is intended for future use on board commercial aircraft. Specifically, the design is intended for the Boeing 787 Dreamliner aircraft, serving as a personal reading light for the passengers seated in the cabin. Most current reading lights on board aircraft are rigid, incandescent, and have very limited freedom in terms of adjusting the emitted light. Incandescent lamps are also inefficient with respect to energy consumption and light output as well as a high heat output. In an economy of increasing demand …

An Analysis Of Stabilizing 3u Cubesats Using Gravity Gradient Techniques And A Low Power Reaction Wheel, Erich Bender

Aerospace Engineering

The purpose of this paper is to determine the feasibility of gravity gradient stabilizing a 3U CubeSat and then using a miniature reaction wheel to further increase stability characteristics. This paper also serves as a guide to understanding and utilizing quaternions in attitude control analysis. The analytical results show that using 33 centimeter booms and 400 gram tip masses, a 3U CubeSat will experience a maximum of 6 degrees of angular displacement in yaw and pitch, and less than .5 degrees of angular displacement in the nadir axis. A .120 kilogram miniature reaction wheel developed by Sinclair Interplanetary was introduced …

Electric Aircraft Propulsion Test Rig Design & Fabrication, Ryan Mayer, Brian Kubicki, Bradley Rodriguez, Austin Harris, David Caudle

Aerospace Engineering

An electric aircraft propulsion test rig was designed and fabricated to predict thrust, torque and battery discharge profiles for an electric aircraft. The original unit was purchased from ElectraFlyer and included the DC brushless motor, carbon fiber propeller, charger, electronic controller and lithium polymer batteries. Various components were constructed and purchased in order to fabricate the optimal test rig apparatus. This apparatus allows for simultaneous measurement of the torque and thrust of the system through the use of a biaxial sensor. The test rig also measures system voltage and current, which allows the user to determine the discharge profile of …

An Investigation Of Dynamic Soaring And Its Applications To The Albatross And Rc Sailplanes, Christopher J. Lee

Aerospace Engineering

Dynamic soaring is a technique used by the sea bird the Albatross. This technique allows for the bird to stay in the air for extended periods of time with very little effort. Dynamic soaring utilizes the wind gradient on the surface of the ocean to maintain its airspeed. A similar technique is used by RC glider pilots to achieve high speeds by using the shear wind layer on the leeward side of mountain ridges.