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Aerospace Engineering Commons™

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2010

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Articles 61 - 90 of 304

Full-Text Articles in Aerospace Engineering

Three-Body Abrasion Testing Using Lunar Dust Simulants To Evaluate Surface System Materials, Ryan L. Kobrick, Kenneth G. Budinski, Kenneth W. Street Jr., David M. Klaus Aug 2010

Three-Body Abrasion Testing Using Lunar Dust Simulants To Evaluate Surface System Materials, Ryan L. Kobrick, Kenneth G. Budinski, Kenneth W. Street Jr., David M. Klaus

Publications

Numerous unexpected operational issues relating to the abrasive nature of lunar dust, such as scratched visors and spacesuit pressure seal leaks, were encountered during the Apollo missions. To avoid reoccurrence of these unexpected detrimental equipment problems on future missions to the Moon, a series of two- and three-body abrasion tests were developed and conducted in order to begin rigorously characterizing the effect of lunar dust abrasiveness on candidate surface system materials. Two-body scratch tests were initially performed to examine fundamental interactions of a single particle on a flat surface. These simple and robust tests were used to establish standardized measurement …

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Kalman Filtering With State Constraints: A Survey Of Linear And Nonlinear Algorithms, Daniel J. Simon Aug 2010

Kalman Filtering With State Constraints: A Survey Of Linear And Nonlinear Algorithms, Daniel J. Simon

Electrical and Computer Engineering Faculty Publications

The Kalman filter is the minimum-variance state estimator for linear dynamic systems with Gaussian noise. Even if the noise is non-Gaussian, the Kalman filter is the best linear estimator. For nonlinear systems it is not possible, in general, to derive the optimal state estimator in closed form, but various modifications of the Kalman filter can be used to estimate the state. These modifications include the extended Kalman filter, the unscented Kalman filter, and the particle filter. Although the Kalman filter and its modifications are powerful tools for state estimation, we might have information about a system that the Kalman filter …

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Investigations Of Femtosecond-Nanosecond Dual-Beam Laser Ablation Of Dielectrics, Cheng Hsiang Lin, Zheng Hua Rao, Lan Jiang, Wu Jung Tsai, Ping Han Wu, Chih Wei Chien, Shean Jen Chen, Hai Lung Tsai Jul 2010

Investigations Of Femtosecond-Nanosecond Dual-Beam Laser Ablation Of Dielectrics, Cheng Hsiang Lin, Zheng Hua Rao, Lan Jiang, Wu Jung Tsai, Ping Han Wu, Chih Wei Chien, Shean Jen Chen, Hai Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We have conducted experimental investigations for the micromachining of dielectrics (fused silica) using an integrated femtosecond (is) and nanosecond (ns) dual-beam laser system at different time delays between the fs and ns pulses. We found that the maximum ablation enhancement occurs when the fs pulse is shot near the peak of the ns pulse envelope. Enhancements up to 13.4 times in ablation depth and 50.7 times in the amount of material removal were obtained, as compared to fs laser ablation alone. the fs pulse increases the free electron density and changes the optical properties of fused silica to have metallic …

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Extension To Multiple Species Of A Two-Equation Turbulence Model For High Speed Flows, Martin Horvath Jul 2010

Extension To Multiple Species Of A Two-Equation Turbulence Model For High Speed Flows, Martin Horvath

Master's Theses - Daytona Beach

The Wilcox (2006) k-co turbulence model has been extended to multiple species and implemented in a CFD code for high speed flows using the Steger-Warming flux-vector splitting scheme. The model was chosen because compressibility corrections are not required, nor are viscous damping factors or wall functions to produce the law of the wall, and it has previously been validated for approximately one hundred test cases ranging from incompressible to hypersonic flow regimes. Initial validation cases using first-order accuracy have been performed, including a Mach 2.5 flow past a backward-facing step and a Mach 2.85 flow into a 24° compression corner. …

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Scan Loss Pattern Synthesis For Adaptive Array Ground Stations, William C. Barott, Mary Ann Ingram, Paul G. Steffes Jul 2010

Scan Loss Pattern Synthesis For Adaptive Array Ground Stations, William C. Barott, Mary Ann Ingram, Paul G. Steffes

Publications

We present several techniques for maximizing the contact time between low Earth orbiting satellites (LEOs) and a ground station (GS). The GS comprises an adaptive array of electronically steered space-fed lenses (SFLs). Each SFL is manufactured as a low-cost printed circuit with the result that it exhibits scanning loss. By differently orienting the boresights of the SFLs in the adaptive array, the SFL's scanning losses can be made to optimally complement the path loss of the LEO, thereby reducing the cost of the GS while maximizing the download capacity of the satellite link. The optimization, implemented with a genetic algorithm …

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Uncertainty Quantification Integrated To The Cfd Modeling Of Synthetic Jet Actuators, Srikanth Adya, Daoru Frank Han, Serhat Hosder Jul 2010

Uncertainty Quantification Integrated To The Cfd Modeling Of Synthetic Jet Actuators, Srikanth Adya, Daoru Frank Han, Serhat Hosder

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Point Collocation Non-Intrusive Polynomial Chaos (NIPC) method has been applied to two stochastic synthetic jet actuator problems used as test cases in the CFDVAL2004 workshop to demonstrate the integration of computationally efficient uncertainty quantification to the high-fidelity CFD modeling of synthetic jet actuators. In Case1 where the synthetic jet is issued into quiescent air, the NIPC method is used to quantify the uncertainty in the long-time averaged u and v-velocities at several locations in the flow field, due to the uniformly distributed uncertainty introduced in the amplitude and frequency of the oscillation of the piezo-electric membrane. Fifth order NIPC …

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Analytic Construction Of Periodic Orbits In The Restricted Three-Body Problem, Mohammed A. Ghazy Jul 2010

Analytic Construction Of Periodic Orbits In The Restricted Three-Body Problem, Mohammed A. Ghazy

Mechanical & Aerospace Engineering Theses & Dissertations

This dissertation explores the analytical solution properties surrounding a nominal periodic orbit in two different planes, the plane of motion of the two primaries and a plane perpendicular to the line joining the two primaries, in the circular restricted three-body problem. Assuming motion can be maintained in the plane and motion of the third body is circular, Jacobi's integral equation can be analytically integrated, yielding a closed-form expression for the period and path expressed with elliptic integral and elliptic function theory. In this case, the third body traverses a circular path with nonuniform speed. In a strict sense, the in-plane …

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The Effect Of Systematic Error In Forced Oscillation Wind Tunnel Test Apparatuses On Determining Nonlinear Unsteady Aerodynamic Stability Derivatives, Brianne Y. Williams Jul 2010

The Effect Of Systematic Error In Forced Oscillation Wind Tunnel Test Apparatuses On Determining Nonlinear Unsteady Aerodynamic Stability Derivatives, Brianne Y. Williams

Mechanical & Aerospace Engineering Theses & Dissertations

One of the basic problems of flight dynamics is the formulation of aerodynamic forces and moments acting on an aircraft in arbitrary motion. Classically conventional stability derivatives are used for the representation of aerodynamic loads in the aircraft equations of motion. However, for modern aircraft with highly nonlinear and unsteady aerodynamic characteristics undergoing maneuvers at high angle of attack and/or angular rates the conventional stability derivative model is no longer valid. Attempts to formulate aerodynamic model equations with unsteady terms are based on several different wind tunnel techniques: for example, captive, wind tunnel single degree-of-freedom, and wind tunnel free-flying techniques. …

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Repeating Ground Track Design For Low Earth Orbit Satellite, Gurkan Gurdal Jul 2010

Repeating Ground Track Design For Low Earth Orbit Satellite, Gurkan Gurdal

Mechanical & Aerospace Engineering Theses & Dissertations

In this thesis, conditions and design requirements for a repeating ground track for a low Earth orbit satellite have been examined and several repeating ground tracks have been designed for a single area on the Earth. In order to construct and validate desired orbital results, the study has two phases which also help to investigate repeating ground track conditions: the fist one is the design phase, and second one is the simulation phase. The common objective of all the case studies is to present a closed ground track on the target by using the design parameters. In order to design …

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Prediction Of The Transport Properties Of A Polyatomic Gas, Zhi Liang, Hai-Lung Tsai Jun 2010

Prediction Of The Transport Properties Of A Polyatomic Gas, Zhi Liang, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An Ab Initio Molecular Potential Model is Employed in This Paper to Show its Excellent Predictability for the Transport Properties of a Polyatomic Gas from Molecular Dynamics Simulations. a Quantum Mechanical Treatment of Molecular Vibrational Energies is Included in the Green and Kubo Integral Formulas for the Calculation of the Thermal Conductivity by the Metropolis Monte Carlo Method. using CO2 Gas as an Example, the Fluid Transport Properties in the Temperature Range of 300-1000 K Are Calculated Without using Any Experimental Data. the Accuracy of the Calculated Transport Properties is Significantly Improved by the Present Model, Especially for the Thermal …

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A Natural Language To Component Term Methodology: Towards A Form Based Concept Generation Tool, Matt Robert Bohm, Robert B. Stone Jun 2010

A Natural Language To Component Term Methodology: Towards A Form Based Concept Generation Tool, Matt Robert Bohm, Robert B. Stone

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Over the last few decades design researchers have put forward theories and proposed methodologies that increase the chance that a design team will reliably arrive at the optimal solution to a given design problem. Studies, however, bear out that theories and methodologies alone will not guarantee an optimal or even good design solution. Instead, a breadth of knowledge across multiple engineering domains and the time and tools to thoroughly evaluate the design space are as important as any prescriptive design method. This work presents one of the underlying engineering technologies needed to leverage artificial intelligence approaches to thoroughly search the …

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Validating Module Heuristics On Large Scale Products, Rachel Day, Robert B. Stone, Katie Grantham Lough Jun 2010

Validating Module Heuristics On Large Scale Products, Rachel Day, Robert B. Stone, Katie Grantham Lough

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Decreasing time and costs is a major objective in many businesses today. Including modularity in the early design phases can effectively decrease time spent on and costs associated with a project. the task of identifying modules within a product early in the design process (when decisions are less expensive) is made less daunting by using the techniques of functional modeling and module heuristics. This paper discusses the results of the initial efforts to verify the module heuristics on large products (products with functional models consisting of more than 30 sub-functions) since the module heuristics were originally developed on small products. …

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Functioncad: A Functional Modeling Application Based On The Function Design Framework, Robert L. Nagel, Kenneth L. Perry, Robert B. Stone, Daniel A. Mcadams Jun 2010

Functioncad: A Functional Modeling Application Based On The Function Design Framework, Robert L. Nagel, Kenneth L. Perry, Robert B. Stone, Daniel A. Mcadams

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents a functional modeling application, Function CAD, based on integrated functional and process modeling within the Function Design Framework. Function CAD provides for mixed, hierarchical models of environment, process and function with relationships represented via flows of material, energy and signal. This paper discusses the technical details of the Function CAD software including its two major components: (1) the library, libFCAD, for handling the internal representation of the model and (2) the GUI for user-Based model manipulation and visualization. the application of Function CAD within a computational, function- based conceptual design process is discussed along with the plugin …

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Velocity Plume Profiles For Hall Thrusters Using Laser Diagnostic, Daniel B. Lee Jun 2010

Velocity Plume Profiles For Hall Thrusters Using Laser Diagnostic, Daniel B. Lee

Theses and Dissertations

This research built a non-intrusive laser diagnostic tool using Laser Induced Fluorescence (LIF) and absorption techniques to measure the velocity and density plume profiles of low powered Hall thrusters. This tool was then applied to a Busek 200W Hall thruster to validate the performance against previous research on the same thruster. A laser frequency sweep through 834.72 nm produced LIF signals for ionized xenon –collected at 541.9 nm – in the thruster plume and absorption data outside the plume at a neutral transition at 834.68 nm. The absorption data provided a baseline reference to calculate the axial and radially velocity …

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An Integrity Framework For Image-Based Navigation Systems, Craig D. Larson Jun 2010

An Integrity Framework For Image-Based Navigation Systems, Craig D. Larson

Theses and Dissertations

This work first examines fundamental differences between measurement models established for GPS and those of proposed image-based navigation systems. In contrast to single value per satellite GPS pseudorange measurements, image measurements are inherently angle-based and represent pixel coordinate pairs for each mapped target. Thus, in the image-based case, special consideration must be given to the units of the transformations between the states and measurements, and also to the fact that multiple rows of the observation matrix relate to particular error states. An algorithm is developed to instantiate a framework for image-based integrity analogous to that of GPS RAIM. The algorithm …

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A Photogrammetry-Based Hybrid System For Dynamic Tracking And Measurement, Daniel P. Magree Jun 2010

A Photogrammetry-Based Hybrid System For Dynamic Tracking And Measurement, Daniel P. Magree

Theses and Dissertations

Noncontact measurements of lightweight flexible aerospace structures present several challenges. Objects are usually mounted on a test stand because current noncontact measurement techniques require that the net motion of the object be zero. However, it is often desirable to take measurements of the object under operational conditions, and in the case of miniature aerial vehicles (MAVs) and deploying space structures, the test article will undergo significant translational motion. This thesis describes a hybrid noncontact measurement system which will enable measurement of structural kinematics of an object freely moving about a volume. By using a real-time videogrammetry system, a set of …

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Matlab Structural Analysis Code For String Wing Box Structure, Sean Brown Jun 2010

Matlab Structural Analysis Code For String Wing Box Structure, Sean Brown

Aerospace Engineering

This report outlines the method used for analysis of a wing box structure for the experimental “stringy” wing structure often used in light RC aircraft. This code is able to find the displacement of each joint, and the stress and forces in each member of the truss structure. It also has the features of load and structure visualization, Kevlar string removal, user-defined point and distributed loading functions, and user-defined failure criteria function. This method and resulting code is meant for use in the support of the Human Powered Helicopter project being undertaken by the Aerospace and Mechanical Engineering Department at …

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Analysis Of A Passive Flow Control Device Via Flow Visualization Techniques, Cheryl R. Graham, Shi (Peter) Huang Jun 2010

Analysis Of A Passive Flow Control Device Via Flow Visualization Techniques, Cheryl R. Graham, Shi (Peter) Huang

Aerospace Engineering

This report details an experiment done to verify the effectiveness of a passive flow control system on a two-dimensional bluff body, blunt trailing edge model in controlling wake dimension and Karman vortex sheds. An earlier experiment by Park, et.al.[1] performed analysis via wind tunnel pressure testing and computerized model to determine the ideal proportions of such a tab design and identify the flow properties responsible for the potential drag reduction. To obtain visual verification of the existence of these concepts, a bluff body model proportionally identical to the one used by Park, et.al., was designed and tested in a water …

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Interplanetary Gravity Assisted Trajectory Optimizer (Igato), Jason Bryan Jun 2010

Interplanetary Gravity Assisted Trajectory Optimizer (Igato), Jason Bryan

Aerospace Engineering

Interplanetary space travel is an extremely complicated endeavor that is severely limited by our current technological advancements. The amount of energy required to transport a spacecraft from one planet to the next, or even further, is extraordinary and in some cases is even impossible given our current propulsive capabilities. Due to these complications, the search for other means of exchanging energy became imperative to future space exploration missions. One particularly powerful method that was discovered, and the most commonly used one, is referred to as planetary gravity assist. In order to plan out multiple gravity assist trajectories, complex and robust …

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Autonomous Control Of The Cal Poly Motion Flight Simulator, Andrew M. Anderson Jun 2010

Autonomous Control Of The Cal Poly Motion Flight Simulator, Andrew M. Anderson

Aerospace Engineering

An autonomous controller for the Cal Poly Motion Flight Simulator was developed such that the simulated Van’s RV-7 flies a standard light aircraft traffic pattern without any human pilot input. First, an autopilot was developed in Simulink to control the aircraft’s altitude, airspeed, and heading independent of each other. The performance of the autopilot has been tested to perform with a response sufficient for precise navigation. A C++ s- function was written as a mission controller that followed a pre-programmed path around a known airport. The aircraft performs a standard left 45 degree entry into the traffic pattern, lands on …

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Analysis Of F-104c World's Altitude Record Flight, William J. Day Jun 2010

Analysis Of F-104c World's Altitude Record Flight, William J. Day

Aerospace Engineering

No abstract provided.

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Design, Fabrication, And Testing Of An Automotive Turbocharger-Based Gas Turbine Engine, John Kyle Thoma, Daniel Shehan, Benjamin Naravage, Jacob Melvin Jun 2010

Design, Fabrication, And Testing Of An Automotive Turbocharger-Based Gas Turbine Engine, John Kyle Thoma, Daniel Shehan, Benjamin Naravage, Jacob Melvin

Aerospace Engineering

A fully-functioning, self-sustaining gas turbine engine was designed and built. The engine was constructed around a Holset HE351 VGT automobile turbocharger, containing compressor and turbine assemblies on a common shaft. Other components of the engine were either purchased or designed and fabricated in-house. During initial testing of the completed engine, the turbocharger, however, was found to have extensive damage to the internal oil seals, and so the project could not be completed as planned. Instead, the combustor design and fabrication was completed for stand-alone testing. The combustion chamber was designed so that the flame tube could be easily changed out …

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Alterations Of The Cal Poly Supersonic Wind Tunnel To Increase Accuracy And Prove The Absence Of Shockwaves, Garrett A. Lovell, Hector A. Gonzalez Jun 2010

Alterations Of The Cal Poly Supersonic Wind Tunnel To Increase Accuracy And Prove The Absence Of Shockwaves, Garrett A. Lovell, Hector A. Gonzalez

Aerospace Engineering

The calibration and improvement of the Cal Poly supersonic wind tunnel was performed in order to create a fully functional facility for supersonic testing. While investigating possible shocks present in the wind tunnel, it was discovered that the real concern was not the tunnel but the measurement systems. Both measurement systems, pitot tube and Schlieren, were evaluated and were found to be deficient. The pitot system had so much play in it that it bent backward every time the tunnel was run invalidating the results, and giving false shock data. The Schlieren system was missing one vital component to make …

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Cal Poly Flight Test Platform For Instrument Development, Kyle Schaller, Ian Muceus, Aaron Ells Jun 2010

Cal Poly Flight Test Platform For Instrument Development, Kyle Schaller, Ian Muceus, Aaron Ells

Aerospace Engineering

This report summarizes a six month effort to conceptually design, develop, and build an unmanned aerial vehicle to test a boundary layer data system (BLDS) developed by Dr. Russell Westphal and his team of mechanical engineering senior design students. The project is funded by Edwards Air Force Base and the United States Air Force Research Laboratory. During the first Cal Poly quarter of project work, January 4, 2010 to March 18, 2010, the team completed a conceptual and preliminary design. During the second quarter, March 18, 2010 to June 12, 2010, the team completed the construction and initial flight test …

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Improved Computational And Experimental Validation Using Different Turbulence Models, Jay Marcos, David D. Marshall Jun 2010

Improved Computational And Experimental Validation Using Different Turbulence Models, Jay Marcos, David D. Marshall

Aerospace Engineering

This paper will explore the methods and techniques necessary to perform a more accurate CFD validation of experimental results. The methods and techniques used will be validated against experimental wind tunnel data of a 2D high lift airfoil with a 3D engine performed by Georgia Tech Research Institute. Preliminary results showed that computational methods over predict the lift and drag coefficient, while still showing very similar trends in CL and CD. To further improve the preliminary results and the predictive capabilities, different turbulence models will be investigated. Results of this validation will assist in determining the appropriate turbulence models, boundary …

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Analysis Of Curvature Effects On Boundary Layer Separation And Turbulence Model Accuracy For Circulation Control Applications, Daniel Wilde Jun 2010

Analysis Of Curvature Effects On Boundary Layer Separation And Turbulence Model Accuracy For Circulation Control Applications, Daniel Wilde

Aerospace Engineering

This set of analyses involves flow separation in high curvature regions with special attention to circulation control implementations. Blown flaps of various shapes designed by Rory Golden for use on the AMELIA, or Advanced Model for Extreme Lift and Improved Aeroacoustics, short takeoff vehicle have exhibited flow separation at locations where flap curvature changes. Investigating this problem, its causes, and potential solutions, I have concluded that the separation is equally a function of the flow simulation turbulence model used, and the geometry of the flap itself. Using Gambit version 11.0.1 for grid generation and Fluent version 6.3.26 for CFD calculations, …

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Hybrid Rocket Motor, Zach Arena, Alexander Athougies, Alden Rodulfo Jun 2010

Hybrid Rocket Motor, Zach Arena, Alexander Athougies, Alden Rodulfo

Aerospace Engineering

This project involves the re-design, manufacturing, and testing of the Cal Poly Space System’s 4th iteration of an M-class 98mm hybrid rocket motor. This motor utilizes hydroxyl-terminated polybutadiene as fuel with liquid nitrous oxide as the oxidizer. Modeling and analysis was conducted on a 12 port self-impinging swirl injector and fuel manufacturing to improve performance. Several hot and cold flow tests were conducted to validate the analysis and predict performance values. Test results included two test fires resulting in an average of 212 lbf of thrust for 6 seconds with an Isp of 160 seconds and an average thrust of …

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Ground Support Equipment For Northrop Grumman Massive Heat Transfer Experiment, Michael A. Manuel, Christopher J. Sparber, Greg A. Trent Jun 2010

Ground Support Equipment For Northrop Grumman Massive Heat Transfer Experiment, Michael A. Manuel, Christopher J. Sparber, Greg A. Trent

Aerospace Engineering

California Polytechnic State University students designed, built, and certified ground support equipment for the Northrop Grumman Massive Heat Transfer Experiment. The Cal Poly design team built the 10000, 20000, and 30000 assemblies to meet Northrop Grumman requirements. The requirements included interface limitations, design load factors, delivery, and testing specifications. The design process consists of requirements generation, conceptual design, preliminary design, design reviews, manufacturing, and certification. The hardware was successfully completed and is used at the Johnson Space and Kennedy Space Center.

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Senior Project: Global Position Determination From Observed Relative Position Of Celestial Bodies, Michael Holmes Jun 2010

Senior Project: Global Position Determination From Observed Relative Position Of Celestial Bodies, Michael Holmes

Aerospace Engineering

A method was developed to determine the latitude and longitude of an observer based on the observed position of the Moon and several other celestial bodies. The basic principal developed dealt with the proximity of the Moon. Its relative displacement from calculated values was measured using photography by comparison with stars near the Moon. Photographs were taken from a location in San Luis Obispo at Longitude 120°35.9' and Latitude 35°13.3'. The analysis method has determined the location of the observer to a Longitude of 117°43.8'. An additional method located the observer to 36°38.7'N Latitude and 114°47.6'W Longitude.

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Conceptual Aircraft Hinge Moment Measurement System, Erin M. Hambrick, Nicole M. Thomason Jun 2010

Conceptual Aircraft Hinge Moment Measurement System, Erin M. Hambrick, Nicole M. Thomason

Aerospace Engineering

The Conceptual Aircraft Hinge Moment Measurement System (CAHMMS) was designed, prototyped, and validated to improve hinge moment estimates early in the design process. Validation was performed by integrating CAHMMS with a test wing and conducting wind tunnel tests to compare the expected theoretical, historical, and Computational Fluid Dynamics (CFD) predictions to the experimental results. As CAHMMS is an external measurement system, interference effects at the connection points were investigated. Further studies were undertaken to verify the CFD predictions with the experimental hinge moment measurements. Hinge moment results from the experimental data and the theoretical data closely correlated with less than …

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