Aerospace Engineering Commons^™

Analysis Of Slewing And Attitude Determination Requirements For Ctex, William J. Starr Jr.

Theses and Dissertations

This thesis examines the slewing and attitude determination requirements for the Chromotomographic Experiment (CTEX), a chromotomographic-based hyperspectral imager, to be mounted on-board the Japanese Experiment Module (JEM) External Facility (EF). The in-track slewing requirement is driven by the facts that CTEx has a very small field of view (FOV) and is required to collect 10 seconds of data for any given collection window. The need to slew in the cross-track direction is a product of the small FOV and target/calibration site access. CTEx incorporates a two-axis slow-steering dwell mirror with a range of ± 8 degrees and an accuracy of …

Mission Analysis For Multiple Rendezvous Of Near-Earth Asteroids Using Earth Gravity Assist, Uriah J. Tobey

Theses and Dissertations

The Jet Propulsion Laboratory (JPL) catalog of near-Earth objects (NEOs) such as asteroids and comets contains over 6600 asteroids and 150 comets as of February of 2010. This includes over 1000 potentially hazardous asteroids, or objects with orbits that pass close enough to Earth to pose a potential impact threat. The asteroid community believes there are a significant number of objects still undiscovered, which makes finding, tracking, and calculating missions to study these objects an active area of research. This study was based on finding orbit solutions using Earth gravity assist to visit one near-Earth object (NEO) a year for …

Part Count: Monolithic Part Effects On Manufacturing Labor Cost, An Aircraft Applied Model, Aaron M. Lemke

Theses and Dissertations

There are significantly different manufacturing processes and part counts associated with composites that are not currently addressed within the aircraft procurement and life cycle management processes in the Department of Defense (DoD). A series of affordability initiatives have culminated in significant evidence over the last decade to better quantify the impact of primarily composite structures in aircraft. An Air Force Research Laboratory program, Advanced Composite Cargo Aircraft (ACCA), provides substantial support for the impact of part size on life cycle cost for payload aircraft. This research evaluates select methods used and seeks to introduce modifications to the projected manufacturing hours …

Mechanical Properties Characterization And Business Case Analysis Of The Fiber Metal Laminate Glare-3 For Use As Secondary Aircraft Structure, Benjamin O. Elton

Theses and Dissertations

This effort explored the mechanical characteristics and economic feasibility of using the fiber metal laminate, GLARE-3, as a secondary aircraft structure; specifically, the cargo floor of a C-130. The mechanical properties were determined through static four-point bending and tensile testing and dynamic impact testing. Aggregate behavior of the constituent materials was predicted using a model which consisted of Mass Volume Fraction (MVF) and Classical Laminated Plate Theory (CLPT) methods using known values for the constituents. Static testing was conducted on coupon-level specimens using standardized testing procedures. Static tensile tests were conducted on specimens with four different fiber orientations, 0°, 22.5°, …

Development Of Morphing Aircraft Structure Using Smp, Soo-Chan Jee

Theses and Dissertations

The U.S Air Force needs new aircraft which provide longer flight time, less fuel consumption, better aerodynamics in order to perform Air Force missions successfully as the mission environment changes rapidly. A morphing wing aircraft is considered as a potential new aircraft for those missions. This thesis explores Shape Memory Polymer (SMP) properties test results and its application for morphing wing skin. Several SMP composite laminates were considered for investigating shape changing characteristics required for morphing skin. The braided composite preforms used in making SMP composites were explored in morphing wing operating system based on the results of property tests. …

Attitude Control Of A Satellite Simulator Using Reaction Wheels And A Pid Controller, Ryan E. Snider

Theses and Dissertations

Attitude requirements of a satellite are determined by its mission: telecommunications, optical imagery, and meteorology to name a few. A satellite's ability to orient its mission critical hardware (solar arrays, attitude sensors, etc.), as well as its mission specific payload, is incumbent upon the performance of the satellite's attitude control system (ACS). For a highly accurate ACS and for moderately fast maneuverability, reaction wheels are preferred because they allow continuous and smooth control while inducing the smallest possible disturbance torques. The objective of this research is to design, build, test, and evaluate the performance of a reaction wheel ACS on-board …

Smore Phase 2: An Upgrade In Valve Systems & Startup Procedure For A Small Methanol Oxygen Liquid Rocket Engine, Christian Soria

Aerospace Engineering

A Methanol-Oxygen liquid rocket engine was designed and manufactured under the California Polytechnic State University Aerospace Department by students in a graduate level rocket propulsion class. The SMORE, previously known as the KORE, is now in an ongoing testing and developing stage with plans to incorporate it into the aerospace undergraduate propulsion lab. Phase 2 of the liquid rocket engine development is to produce a start-up procedure that will improve the safety due to manual operation and poor ignition conditions. A propane ignition system along with the implementation of electrically operated solenoid valves to control the fuels and oxidizer were …

Quantifying Seismic Risk For Portable Ground Support Equipment At Vandenberg Air Force Base, Joshua Brian Lowe

Master's Theses

This project develops a quantitative method to evaluate the seismic risk for portable GSE at Vandenberg Air Force Base. Using the latest probability data available from the USGS, risk thresholds are defined for portable GSE having the potential to cause a catastrophic event. Additionally, an example tool for design engineers was developed from the seismic codes showing the tipping hazard case can be simplified into strict geometrical terms. The misinterpretation and confusion regarding the Range Safety 24 Hour Rule exemption can be avoided by assessing seismic risk for portable GSE. By using the methods herein to quantify and understand seismic …

Modeling Disk Cracks In Rotors By Utilizing Speed Dependent Eccentricity, Andrew L. Gyekenyesi, Jerzy T. Sawicki, Wayne C. Haase

Mechanical Engineering Faculty Publications

This paper discusses the feasibility of vibration-based structural health monitoring for detecting disk cracks in rotor systems. The approach of interest assumes that a crack located on a rotating disk causes a minute change in the system’s center of mass due to the centrifugal force induced opening of the crack. The center of mass shift is expected to reveal itself in the vibration vector (i.e., whirl response; plotted as amplitude and phase versus speed) gathered during a spin-up and/or spin-down test. Here, analysis is accomplished by modeling a Jeffcott rotor that is characterized by analytical, numerical, and experimental data. The …

Autonomous Satellite Operations For Cubesat Satellites, Jason Lionel Anderson

Master's Theses

In the world of educational satellites, student teams manually conduct operations daily, sending commands and collecting downlinked data. Educational satellites typically travel in a Low Earth Orbit allowing line of sight communication for approximately thirty minutes each day. This is manageable for student teams as the required manpower is minimal. The international Global Educational Network for Satellite Operations (GENSO), however, promises satellite contact upwards of sixteen hours per day by connecting earth stations all over the world through the Internet. This dramatic increase in satellite communication time is unreasonable for student teams to conduct manual operations and alternatives must be …

System Integration And Attitude Control Of A Low-Cost Spacecraft Attitude Dynamics Simulator, Ryan L. Kinnett

Master's Theses

The CalPoly Spacecraft Attitude Dynamics Simulator mimics the rotational dynamics of a spacecraft in orbit and acts as a testbed for spacecraft attitude control system development and demonstration. Prior to this thesis, the simulator platform and several subsystems had been designed and manufactured, but the total simulator system was not yet capable of closed-loop attitude control. Previous attempts to make the system controllable were primarily mired by data transport performance. Rather than exporting data to an external command computer, the strategy implemented in this thesis relies on a compact computer onboard the simulator platform to handle both attitude control processing …

Combined H∞-Feedback Control And Iterative Learning Control Design With Application To Nanopositioning Systems, Brian E. Helfrich, Chibum Lee, Douglas A. Bristow, Jingyan Dong, Srinivasa M. Salapaka, Placid M. Ferreira, X. H. Xiao, Andrew G. Alleyne

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper examines a coordinated feedback and feedforward control design strategy for precision motion control (PMC) systems. It is assumed that the primary exogenous signals are repeated; including disturbances and references. Therefore, an iterative learning control (ILC) feedforward strategy can be used. The introduction of additional non-repeating exogenous signals, including disturbances, noise, and reset errors, necessitates the proper coordination between feedback and feedforward controllers to achieve high performance. A novel ratio of repeated versus non-repeated signal power in the frequency domain is introduced and defined as the repetitive-to-non-repetitive (RNR) ratio. This frequency specific ratio allows for a new approach to …

Three-Dimensional Modeling Of Transport Phenomena And Their Effect On The Formation Of Ripples In Gas Metal Arc Welding, Z. H. Rao, J. Zhou, S. M. Liao, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Distinct, periodic arc-shaped ripples are observed on the surface of the weld bead in almost any welded components which have a significant effect on weld quality. This article presents the complex transport phenomena and their effect on the formation of ripples in three-dimensional moving gas metal arc welding. The transient distributions of the melt flow velocity and temperature in the weld pool, weld pool shape and dynamics, and solidified weld bead are calculated. It is found that the surface ripples are formed by the interplay between the up-and-down weld pool dynamics, caused mainly by the periodic droplet impingements, and the …

Parametric Viscous Analysis Of Gust Interaction With Stationary And Elastically Mounted Airfoil, Timothy M. Hollenshade Jr.

Master's Theses - Daytona Beach

This thesis details the development and implementation of a module within a high-accuracy numerical viscous analysis code to simulate the nonlinear interaction of SD7003 airfoil with non-uniform, unsteady incoming flow. The study is focused on the low-Re number unsteady flows typical of MAV applications in which a gust encounter can induce a particularly significant aerodynamic and aeroelastic response. Efficient source models are developed to introduce sharp-edge and time-harmonic gust perturbations with specified amplitude, frequency and duration inside the computational domain through the source terms in the governing momentum equations. Parametric analysis of gust-airfoil interactions for different steady airfoil loads is …

Adaptive Control Applied To The Cal Poly Spacecraft Attitude Dynamics Simulator, Matthew C. Downs

Master's Theses

The goal of this thesis is to use the Cal Poly Spacecraft Attitude Dynamics Simulator to provide proof of concept of two adaptive control theories developed by former Cal Poly students: Nonlinear Direct Model Reference Adaptive Control and Adaptive Output Feedback Control. The Spacecraft Attitude Dynamics Simulator is a student-built air bearing spacecraft simulator controlled by four reaction wheels in a pyramidal arrangement. Tests were performed to determine the effectiveness of the two adaptive control theories under nominal operating conditions, a “plug-and-play” spacecraft scenario, and under simulated actuator damage. Proof of concept of the adaptive control theories applied to attitude …

Control Law Design And Validation For A Helicopter In-Flight Simulator, Brian T. Fujizawa

Master's Theses

In-flight simulation allows one aircraft to simulate the dynamic response of another aircraft. A control system designed to give RASCAL, a JUH-60A Black Hawk helicopter based at Moffett Field, CA, in-flight simulation capabilities has been designed, optimized and validated in this research. A classical explicit model following control system with a frequency dependent feedback controller was used. The frequency dependent controller allows model following of the attitude in the short term and the velocity in the long term. Controller gains were optimized using a high order, linearized model of UH-60 dynamics. Non-linear simulations of the control laws were performed, first …

Constrained Kalman Filtering Via Density Function Truncation For Turbofan Engine Health Estimation, Daniel J. Simon, Donald L. Simon

Electrical and Computer Engineering Faculty Publications

Kalman filters are often used to estimate the state variables of a dynamic system. However, in the application of Kalman filters some known signal information is often either ignored or dealt with heuristically. For instance, state variable constraints (which may be based on physical considerations) are often neglected because they do not fit easily into the structure of the Kalman filter. This article develops an analytic method of incorporating state variable inequality constraints in the Kalman filter. The resultant filter truncates the probability density function (PDF) of the Kalman filter estimate at the known constraints and then computes the constrained …

Effects Of Shielding Gas Compositions On Arc Plasma And Metal Transfer In Gas Metal Arc Welding, Z. H. Rao, S. M. Liao, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This article presents the effects of shielding gas compositions on the transient transport phenomena, including the distributions of temperature, flow velocity, current density, and electromagnetic force in the arc and the metal, and arc pressure in gas metal arc welding of mild steel at a constant current input. The shielding gas considered includes pure argon, 75% Ar, 50% Ar, and 25% Ar with the balance of helium. It is found that the shielding gas composition has significant influences on the arc characteristics; droplet formation, detachment, transfer, and impingement onto the workpiece; and weld pool dynamics and weld bead profile. As …

Improved Geometry Modeling For High Fidelity Parametric Design, James R. Gloudemans, Robert A. Mcdonald

Aerospace Engineering

Advanced multidisciplinary physics-based design and analysis capabilities are required to pursue the revolutionary vehicle and technology concepts needed to meet the goals of the aerospace industry for the next 10-30 years. The multidisciplinary physics critical to advancing aerospace technology all have one common bond, the shape, size, and form of the underlying aircraft - its geometry. An aircraft shape is the natural starting point for multidisciplinary analysis and optimization (MDAO). Vehicle Sketch Pad (VSP) is an aircraft geometry tool for rapid evaluation of advanced design concepts which was developed by NASA and is available to industry at large. VSP allows …

Conceptual Design Of A Next Generation, 150 Passenger Commercial Transport, Ryan Halper, Kevin Lane, Dustin Marschik, Brett Morham, John Pham, Robert A. Mcdonald, Bruce Wright

Aerospace Engineering

In response to the 2008-2009 AIAA Undergraduate Team Design Competition's Request for Proposals for an advanced, environmentally compatible, 150 seat commercial transport; Jackson West has designed the Sparrow JS-3. The Sparrow represents the next step in the evolution of commercial aviation. Scheduled to enter service in 2018, The Sparrow will compete directly with the Boeing 737 and Airbus A320. Its improvements in fuel consumption and operating cost, as well as its reduced environmental impact, make The Sparrow the ideal solution to this RFP.

Assessment Of Sting Effect On X-31 Aircraft Model Using Cfd, Adam Jirásek, Russell M. Cummings

Aerospace Engineering

The article describes the computational evaluation of the effect a belly mounted sting on the aerodynamics characteristics of an X-31 wind tunnel model. The investigation includes results of steady and time-dependent CFD analysis of the X-31 model with and without sting. The values of the steady lift and pitching moment coefficients as well as the pitching moment of model undergoing a manuever are compared to each other and to the wind tunnel data. The results of this analysis show the detrimental effect of sting on stability of the vortical structure above the wing as well as a substantial increase of …

Overview Of Recent Circulation Control Modeling Activities At Cal Poly, David D. Marshall, Kristina K. Jameson

Aerospace Engineering

This paper provides an overview of the Circulation Control modeling research that has been performed, and is still ongoing, at Cal Poly, San Luis Obispo. This work started in 2005 with the interest of applying Circulation Control technologies to advanced aircraft designs. After the initial investigations into this, it was apparent that there was a long history of experimental work in this area to build on, but a number of deficiencies existed in the modeling capabilities. For Circulation Control enabled aircraft, these included: few available tools to accurately model the takeoff and landing performance, the limitations in the standard regulations …

Improved Methodologies For Maneuver Design Of Aircraft Stability And Control Simulations, Adam Jirásek, Tiger L. Jeans, Mathew Martenson, Russell M. Cummings, Keith Bergeron

Aerospace Engineering

With many modern fighter aircraft experiencing unpredicted flight dynamics during flight tests, recent research has focused on developing methodologies for incorporating computational fluid dynamics into the aircraft development process. The goal of this approach is to identify configurations susceptible to stability and control issues early in the design process. Previous research has primarily focused on full aircraft configurations, however, to increase the rate of development the current study focused on a two-dimensional NACA0012 airfoil. The two-dimensional NACA0012 airfoil has the advantage of reducing the computational cost by orders of magnitude compared to full scale aircraft simulations, while still providing complicated …

Parameter Estimation Of Fundamental Technical Aircraft Information Applied To Aircraft Performance, Mike Vallone, Robert A. Mcdonald

Aerospace Engineering

Inverse problems can be applied to aircraft in many areas. One of the disciplines within the aerospace industry with the most openly published data is in the area of aircraft performance. Many aircraft manufacturers publish performance claims, flight manuals and Standard Aircraft Characteristic (SAC) charts without any mention of the more fundamental technical information such as C_D0. With accurate tools, generalized aircraft models and a few curve-fitting techniques, it is possible to evaluate vehicle performance and estimate these technical parameters.

With this goal a program has been written in Matlab to calculate the fundamental information behind a …

Designing A Green Aircraft: Cal Poly's 2009 Undergraduate Aircraft Designs, Robert A. Mcdonald, Bruce Wright

Aerospace Engineering

The Cal Poly senior design class submitted six designs this year in response to the 2009 Undergraduate Team Aircraft Design Competition. This paper summarizes our experiences teaching design through this RFP and brings the student's insights together.

Conceptual Design Of An Environmentally Responsible 150-Passenger Commercial Aircraft, Natalie R. Smith, Bryan Blessing, James Dixon, Allen Mackey, Gregory Mckenzie, Robert A. Mcdonald, Bruce Wright

Aerospace Engineering

Verde is an environmentally responsible commercial transport seating 150 dual-class passengers, designed in response to the 2008-2009 Request for Proposal from the American Institute of Aeronautics and Astronautics Undergraduate Team Aircraft Design Competition. While the airline industry faces increasing pressures from the cost of fuel and the responsibility of environmental impact, the next generation of this aircraft class must operate more efficiently and address those environmental needs. Therefore, all design decisions for Verde focused first on reducing fuel burn, second on reducing emissions, then noise, and finally on maintaining flyaway cost, airport integration, and passenger comfort. The final design utilizes …

Lift Superposition And Aerodynamic Twist Optimization For Achieving Desired Lift Distributions, Kevin A. Lane, David D. Marshall, Robert A. Mcdonald

Aerospace Engineering

A method for achieving an arbitrary lift distribution with an arbitrary planform is presented. This is accomplished through optimizing aerodynamic twist for a given number of either known airfoils or airfoils to be designed. The spanwise locations of these airfoils are optimized to get as close to the desired lift distribution as possible. Airfoils are linearly interpolated between these points. After aerodynamic twist, the planform is twisted geometrically using radial basis functions to model the twist distribution. The aerodynamic influence of each twist distribution is determined and all are superimposed to determine the function weights of each twist function, yielding …

A Three Dimensional Vortex Particle-Panel Method For Modeling Propulsion-Airframe Interaction, Jacob S. Calabretta, Robert A. Mcdonald

Aerospace Engineering

The panel code has been a pivotal tool for aerodynamic simulations for decades, today providing users with quick solutions without the necessity of a volume grid. Unfortunately, the panel code also carries with it some inherent shortcomings when compared with other methods. One such weakness is its inability to account for any work done on or by the system in question. This paper proposes a method to address this issue by combining vortex particles with a panel code, and using them to model the work effects of a propeller or engine. While the proposed model is still a work in …

Computational And Experimental Comparison Of A Powered Lift, Upper Surface Blowing Configuration, Jay Marcos, David D. Marshall

Aerospace Engineering

This paper demonstrates the use of CFD as a validation tool for wind tunnel data on 2D high lift airfoil with a 3D engine performed by Georgia Tech Research Institute. Results of this validation will assist in determining the appropriate turbulence models, boundary conditions, mesh characteristics and other CFD modeling techniques necessary to capture the complicated flow physics associated with the coupling of circulation control wings and engine exhaust flows. It was found that grid issues and the two-equation turbulence model, k-ε, over predicted lift as blowing momentum increases even with the additional complexity of having an over the wing …

Design And Performance Of Circulation Control Flap Systems, Rory M. Golden, David D. Marshall

Aerospace Engineering

The design of circulation control (CC) dual radius flap systems were investigated to characterize the parameters that make up the flap surface to offer further knowledge into the CC field of study. Multiple dual radius flap geometries, along with variants, were developed by varying specific flap parameters from a baseline configuration that had previously developed. The aerodynamics of the different flap geometries were analyzed using two-dimensional CFD. This research will explore the design of CC pneumatic flap systems to improve the performance of existing CC flap configurations, and provide insight into the characteristics of the CC flap geometry.