Aerospace Engineering Commons^™

Orbital Propagators For Horizon Simulation Framework, Mitra Farahmand

Master's Theses

This thesis describes the models of four common orbital propagators and outlines the process of integrating them into the Horizon Simulation Framework (HSF). The results of the Two-Body, J2, and J4 propagators from the HSF are then compared against the outcomes of these propagators in MATLAB and Satellite Toolkit (STK). The MATLAB algorithms verify the functionality of the propagators and determine the accuracy of the HSF implementation. The compassion against STK validates the formulation of the HSF propagators. In order to equip the HSF with a more precise means of orbit determination, adding the Simplified General Perturbations 4 (SGP4) propagator …

Rayleigh Flow Of Two-Phase Nitrous Oxide As A Hybrid Rocket Nozzle Coolant, Lauren May Nelson

Master's Theses

The Mechanical Engineering Department at California Polytechnic State University in San Luis Obispo currently maintains a lab-scale hybrid rocket motor for which nitrous oxide is utilized as the oxidizer in the combustion system. Because of its availability, the same two-phase (gas and liquid) nitrous oxide that is used in the combustion system is also routed around the throat of the hybrid rocket’s converging-diverging nozzle as a coolant. While this coolant system has proven effective empirically in previous tests, the physics behind the flow of the two-phase mixture is largely unexplained. This thesis provides a method for predicting some of its …

Spacecraft Attitude Control (Mission Design), Norhizam Hamzah

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Norhizam Hamzah titled "Spacecraft Attitude Control (Mission Design)" from September 10, 2009.

Turkish Satellite Technology Applications For Sustainable Development And Capacity Building, Burcu Dikmen

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Burcu Dikmen titled "Turkish Satellite Technology Applications for Sustainable Development and Capacity Building" from September 8, 2009.

The Role Of Education In Small Satellite Programmes, Olaleye Salu

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by Olaleye Salu titled "The Role of Education in Small Satellite Programmes" from September 9, 2009.

Unmanned Aircraft System Propulsion Systems Technology Survey, Christopher Griffis, Timothy Wilson, Jeffrey Schneider, Peter Pierpont

Publications

This technology survey is an investigation of various propulsion systems used in Unmanned Aircraft Systems (UAS). Discussed are existing and near-future propulsion mechanisms of UAS, such as reciprocating piston engines, Wankel rotary engines, gas turbine engines, rocket-powered systems, electric motors, and battery-based systems. Also discussed are systems that use proton exchange membrane fuel cells, photovoltaics, ultracapacitors, and propellers. Each system is described in reference to a larger conceptual framework, with instances and profiles of existing UAS employing the system being described. Advantages and disadvantages of each type of propulsion system are identified along with associated technical issues and their respective …

Heavy-Fueled Intermittent Ignition Engines: Technical Issues, Jeffrey Arthur Schneider, Timothy Wilson, Christopher Griffis, Peter Pierpont

Publications

This report contains an overview of the technology and engineering issues with nonturbine heavy-fueled engines for general aviation aircraft and Unmanned Aircraft Systems. In recent years, interest in these types of engines has grown, partly due to the cost, safety, and worldwide availability of gasoline fuels. Within 3 to 5 years, up to five engines will seek Federal Aviation Administration certification as heavy-fuel powerplants. Although there has been some progress, there is no universal standard for certification of these engines (under Title 14 Code of Federal Regulations (CFR) Part 33), or their installation into normal category fixed-wing aircraft or rotorcraft …

The Interaction Between Throttling And Thrust Vectoring Of An Annular Aerospike Nozzle, David Michael Imbaratto

Master's Theses

Applied research and testing has been conducted at the Cal Poly San Luis Obispo High-pressure Blow-Down facility to study the affects of throttling in a thrust-vectored aerospike nozzle. This study supports the ongoing research at Cal Poly to effectively thrust vector a hybrid rocket motor. Such thrust vectoring is achieved by small secondary ports in the nozzle body that are perpendicular to the main nozzle. The testing conducted included characterizing and comparing the performance of a straight aerospike nozzle to that of a thrust-vectored aerospike nozzle. Throttling effects on the aerospike nozzle in an unvectored and in a vectored configuration …

The Navigation Potential Of Ground Feature Tracking, Guner Mutlu

Theses and Dissertations

This research effort examines the reduction of error in inertial navigation aided by vision. This is part of an effort focused on navigation in a GPS denied environment. The navigation concept examined here consists of two main steps. First, extract the position of a tracked ground object using vision and geo-locate it in 3 dimensional navigation frame. In this first step multiple positions of the UAV are assumed known; think of a synthetic aperture. The only information about the tracked ground objects/features is the unit vector that points to the objects from the center of the camera. Two such vectors …

Phase Change Mechanisms During Femtosecond Laser Pulse Train Ablation Of Nickel Thin Films, Xin Li, Lan Jiang, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The mechanisms of nickel thin films irradiated by femtosecond laser pulse trains are studied by a model using molecular dynamics simulations and two-temperature model. It is found that the pulse train technology can change energy transport and corresponding phase change processes. Compared with single pulse ablation at the same total fluence, the pulse trains lead to (1) lower ablation rate with more and smaller uniform nanoparticles, (2) higher film surface temperatures and longer thermalization time, (3) much lower electron thermal conductivity that can further control heat-affected zone, (4) significantly smaller film compressive stresses and tensile stresses which reduce microcracks, and …

Formation Flight Of Earth Satellites On Kam Tori, Christopher T. Craft

Theses and Dissertations

Kolmogorov, Arnold and Moser (KAM) theory provides that orbits of satellites whose dynamics are representable by an integrable Hamiltonian plus a small, real perturbation lie on tori in phase space and remain on the KAM tori for all time, unless acted upon by a non-conservative force. A refined technique for constructing KAM tori for Earth-orbiting satellites is developed and implemented using numerically integrated orbital data for hypothetical satellites and involving methods of Fourier analysis and spectral decomposition. Definition of satellite formations on the KAM tori is performed and analyses conducted to investigate both constellations with large separations and clusters with …

Efficient Simulation Of Fluid Flow, David Hannasch, Monika Neda

Undergraduate Research Opportunities Program (UROP)

We are computationally investigating fluid flow models for physically correct predictions of flow structures. Models based on the idea of filtering the small scales/structures and also the Navier-Stokes equations which are the fundamental equations of fluid flow, are numerically solved via the continuous finite element method. Crank-Nicolson and fractional-step theta scheme are used for the discretization of the time derivative, while the Taylor-Hood and Mini elements are used for the discretization is space. The effectiveness of these numerical discretizations in time and space are examined by studying the accuracy of fluid characteristics, such as drag, lift and pressure drop.

Evaluation Of Direct Diode Laser Deposited Stainless Steel 316l On 4340 Steel Substrate For Aircraft Landing Gear Application, Tian Fu, Todd E. Sparks, Frank W. Liou, Joseph William Newkirk, Zhiqiang Fan, Syamala Rani Pulugurtha, Jianzhong Ruan, Hsin-Nan Chou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

300M steel is used extensively for aircraft landing gears because of its high strength, ductility and toughness. However, like other high-strength steels, 300M steel is vulnerable to corrosion fatigue and stress corrosion cracking, which can lead to catastrophic consequences in the landing gear. Stainless steels offer a combination of corrosion, wear, and fatigue properties. But for an aircraft landing gear application a higher surface hardness is required. A laser cladding process with fast heating and cooling rates can improve the surface hardness. AISI 4340 steel is used as a lower cost alternative to 300M due to its similar composition. In …

Development Of A High Performance Micropropulsion System For Cubesats, Christopher Lorian Biddy

Master's Theses

Picosatellites are defined as satellites with a mass between 0.1 and 1kg (Miniaturized satellite). Picosatellites are typically designed to work together or function in formations (Miniaturized satellite). A specific type of Picosatellite known as CubeSats were introduced in 1999 and since then have increased in popularity so that there are now over 80 CubeSat programs around the world. CubeSats are defined as cubic units 10cm on each side and no more than 1kg in mass. CubeSats are required to conform to the CubeSat Standard created by California Polytechnic State University and Stanford University and be compatible with Cal Poly’s P-POD …

Developing Abrasion Test Standards For Evaluating Lunar Construction Materials, Ryan L. Kobrick, David M. Klaus, Kenneth W. Street

Publications

Operational issues encountered by Apollo astronauts relating to lunar dust were catalogued, including material abrasion that resulted in scratches and wear on spacesuit components, ultimately impacting visibility, joint mobility and pressure retention. Standard methods are being developed to measure abrasive wear on candidate construction materials to be used for spacesuits, spacecraft, and robotics. Calibration tests were conducted using a standard diamond stylus scratch tip on the common spacecraft structure aluminum, Al 6061-T6. Custom tips were fabricated from terrestrial counterparts of lunar minerals for scratching Al 6061-T6 and comparing to standard diamond scratches. Considerations are offered for how to apply standards …

Magnetic Stabilization Of Nadir-Pointing Small Satellites, Chau T. Ton

Master's Theses - Daytona Beach

Since magnetic control systems are relatively lightweight, require low power and are inexpensive, they are attractive for small, inexpensive satellites in low Earth orbits. In this thesis we present averaging-based feedback control laws that achieve three-axis stabilized nadir-pointing attitude. Two types of nonlinear feedback control laws are proposed: full-state feedback and passivity-based feedback. Full-state feedback uses the attitude and angular velocity measurements to regulate the spacecrafts dynamics. Passivity-based feedback uses the attitude measurement and doesn’t require the rate sensors. The control laws are tested using two magnetic field models: the tilted dipole model and the International Geomagnetic Reference Field (IGRF) …

An Intelligible Software (Cfa) Approach For Fiber-Reinforced Laminate Failure Analysis Including A Piecewise Representation Of The Tsai-Wu Failure Criterion Using Excel And Matlab, Ryan C. Schmidt

Master's Theses - Daytona Beach

Present generations rely heavily on the use of petroleum as their primary means of transportation. As the cost of petroleum continues to escalate, the need for lightweight structures for vehicle applications becomes more evident. The ability to engineer materials so that they possess desired application specific properties and characteristics has made tremendous progress in the past century. Consequently, the use of these composite materials for aircraft weight reduction has been investigated for decades.

The aerospace industry often uses composite materials to make a laminated composite structure where each constituent ply of the laminate has its own material properties. This anisotropic …

Section Abstracts: Aeronautical And Aerospace Sciences

Virginia Journal of Science

Abstracts of the Aeronautical and Aerospace Sciences Section for the 87th Annual Meeting of the Virginia Academy of Science, May 27-29, 2009, Virginia Commonwealth University, Richmond, Virginia.

A Study Of Decision Analysis Methods In Aerospace Technology Assessments, Sharon Monica Jones

Engineering Management & Systems Engineering Theses & Dissertations

Managers of aerospace technology programs and projects are faced with the challenge of making technology portfolio decisions under conditions of limited data, rapidly changing macro level factors and organizational uncertainties. To help make these technology investment decisions, some aerospace managers and analysts have used techniques from the field of decision analysis. In addition, there have been a limited number of research studies of real decision problems.

This dissertation presents the results of a non-experimental examination of the use of decision analysis methods for the assessment of aerospace technology portfolios. A web-based survey instrument was developed based on the results of …

On-Board Orbit Determination And 3-Axis Attitude Determination For Picosatellite Applications, John Arthur Bowen

Master's Theses

This thesis outlines an orbit determination and 3-axis attitude determination system for use on orbit as applicable to 1U CubeSats and other picosatellites. The constraints imposed by the CubeSat form factor led to the need for a simple configuration and relaxed accuracy requirements. To design a system within the tight mass, volume, and power constraints inherent to CubeSats, a balance between hardware complexity, software complexity and accuracy is sought. The proposed solution consists of a simple orbit propagator, magnetometers with a magnetic field look-up table, Sun sensors with an analytic Sun direction model, and the TRIAD method to combine vector …

Access Mars: Assessing Cave Capabilities Establishing Specific Solutions: Final Report, Abdul Mohsen Al Husseini, Luis Alvarez Sanchez, Konstantinos Antonakopoulos, Jeffrey (Johannes) Apeldoorn, Kenneth Lowell Ashford Jr., Kutay Deniz Atabay, Sara Langston, Et Al.

Publications

The human race has evolved, grown and expanded through the exploration of Earth. After initial steps on the Moon, our next challenge is to explore the solar system. Mars shows potential for both scientific discovery and future human settlement, and so is a prime candidate for the next leap of human exploration. Such a bold endeavor will be a driver for an unprecedented worldwide cooperative effort and the catalyst for a new era of international, intercultural and interdisciplinary human relations. Scientific and technological progress will also accelerate as mankind is ushered into a new era of space exploration.

Currently proposed …

Stability Analysis, Modeling, Simulation And Experimental Testing Of An Ems Maglev System With Structural Flexibility, Aravind M. Hanasoge

Mechanical & Aerospace Engineering Theses & Dissertations

Vehicle-guideway interaction studies of Magnetically Levitated (Maglev) vehicles indicate that structural flexibility can adversely affect the overall stability and performance of such systems. This is one of the reasons why guideways are generally made very rigid. This in turn leads to increased cost of the overall system since guideway construction forms a significant portion of the overall cost. In this dissertation, the influence of structural flexibility on the stability of Electromagnetic Suspension (EMS) Maglev systems is studied. It is shown how inherently unstable and flexible structure EMS Maglev systems can achieve guaranteed stability by using collocated actuators and sensors, along …

Application Of Volterra Functions To X-31 Aircraft Model Motion, United States Air Force Academy, Russell M. Cummings

Aerospace Engineering

Recent advances towards an efficient computational method for accurately determining the stability and control characteristics of an aircraft are discussed and critiqued. The present approach with greatest promise is to reduce the number of high-fidelity CFD simulations by using Volterra functions Reduced Order Modeling. This type of reduced order model is a predictive model which has a unique training maneuver -a unit impulse. The advantage of such an approach is the fast prediction of the aerodynamic characteristics of an aircraft. This article presents the results of application of the Volterra functions ROM for prediction of linear movement of a 2D …

Comparison Of Overset Grid And Grid Deformation Techniques Applied To 2-Dimensional Naca Airfoils, Charles M. Hoke, Robert K. Decker, Russell M. Cummings, David R. Mcdaniel, Scott A. Morton

Aerospace Engineering

This paper documents a comparison of overset grid and grid deformation schemes applied to flapped and non-flapped NACA airfoil configurations in order to determine the relative accuracy and computational efficiency of each method. This study is part of a larger effort to use computational fluid dynamics to perform moving control surface calculations. Three different cases, using both overset and deformed grids, are considered, including: a) lift and moment comparison of a quasi-steady, non-flapped 0012 airfoil, b) lift and moment comparison of a dynamically pitching non-flapped 0012 airfoil, and c) lift comparison of a dynamic pitching and oscillating flapped 0012 airfoil. …

Effects Of Prior Aging At 288°C In Argon Environment On Creep Response Of Carbon Fiber Reinforced Pmr-15 Composite With ±45°Fiber Orientation At 288°C, Tyler F. Gruters

Theses and Dissertations

The creep and recovery response of carbon fiber reinforced PMR-15 composite with a ±45 fiber orientation was examined in an argon environment at 288°C. Mechanical testing was executed for unaged specimens as well as specimens aged up to 1000 hours. Tensile tests were performed to determine Young's modulus of elasticity and ultimate tensile strength. The creep tests were carried out at stress levels of 30 and 60 MPa. Creep periods of 25 hours were followed by recovery periods of 50 hours at zero stress. Weight loss measurements as a function of aging time were taken as well. The accumulated creep …

Aeroelastic Optimization Of Sounding Rocket Fins, Joseph R. Simmons Iii

Theses and Dissertations

This research effort develops a multidisciplinary design tool to optimize sounding rocket fin geometries that minimize the mass of the fins while maintaining aerodynamic performance. This research grew out of a design problem experienced by the US Air Force Academy's Falcon LAUNCH program. The Falcon LAUNCH program is a senior design capstone project during which Air Force Academy cadets design, build and fly a sounding rocket over the course of an academic year. In the Spring of 2007, the Falcon LAUNCH V vehicle experienced a catastrophic failure when three of its four fins sheared off due to flutter. When the …

Cavity Coupled Aeroramp Injector Combustion Study, Dell T. Olmstead

Theses and Dissertations

The difficulties with fueling of supersonic combustion ramjet engines with hydrocarbon based fuels presents many challenges that are currently being tackled by the Air Force Research Lab Propulsion Directorate Aerospace Propulsion Division. As the scramjet engine designs are scaled up, the need for a better solution to supersonic mixing has led to the development of many different styles of fuel injection. An aerodynamic ramp injector has been shown to have a quantitative improvement over a physical ramp while still achieving desirable mixing characteristics. The objectives for this research was quantifying the performance and operability implications of replacing four 15 degree …

Performance And Operability Of A Dual Cavity Flame Holder In A Supersonic Combustor, Mackenzie J. Collatz

Theses and Dissertations

The current generation of hydrocarbon fueled scramjet combustors typically requires a flame holding device to facilitate flame ignition and stable combustion. The amount of time available for fuel injection, fuel-air mixing, and combustion is very short, on the order of 1 millisecond. This short dwell time, along with the relatively long ignition delay times of hydrocarbon fuels, makes the flow path and flame holder design extremely important. This study investigates the performance and operability of using a symmetric dual cavity flame holder flow path to stabilize and enhance supersonic combustion. Testing of this flow path configuration, as well as a …

Satellite Formation Flight Navigation Using The Clohessy-Wiltshire Equations, Anna Kimmich

Aerospace Engineering

This report presents the design and simulation of a satellite navigation program using Matlab. The program allows any number of independent satellites to navigate in a co-planar cluster formation in a circular orbit with no input besides its location coordinates from a simulated GPS unit and the relative location of other satellites from a simulated on-board sensor. This navigation program uses a potential field-like function to calculate the desired satellite position within the formation. It uses the Clohessy-Wiltshire equations to calculate the impulsive maneuvers needed to achieve and maintain the formation.

Chilling Out In The Sim: The Need For Icing Training., Nihad E. Daidzic

Aviation Department Publications

No abstract provided.