Aerospace Engineering Commons^™

Application Of Kriging To Motorsport Aerodynamic Analysis, Matthew Cruickshank, Graham Doig

Aerospace Engineering

Aerodynamic analysis in motorsport is conducted using three methods, computational, scaled experimental and full-scale operational. However, the varying fidelity, different sampling resolutions and unavoidable errors of each technique make valid comparisons between datasets from each method difficult and time consuming. Kriging is a geostatistical method to estimate values within a data field by examining and applying the trends of the dataset. This research examines how such techniques can be used to aid comparison between aerodynamic measurements of a race car. It examines how kriging can be used to transform discrete measurements, of varying fidelity and sampling resolution, into semi-continuous measurements, …

Computational Simulation Of An Altitude Adaptive Nozzle Concept, K. Schomberg, G. Doig, J. Olsen

Aerospace Engineering

A computational analysis of an annular converging-diverging (CD) and an altitude adaptive expansion-deflection (ED) nozzle is presented. Numerical results were generated using a 2D axisymmetric, pressure-coupled solver in conjunction with the Spalart-Allmaras turbulence closure model and second order spatial discretisation schemes. Results were recorded over a theoretical altitude range and compared to experimental static pressure readings and schlieren images. The correlation between numerical and experimental static pressure values was high for all cases. Comparison of schlieren imagery outlined the large variety of flow regions within the ED nozzle flow field. The interactions between these regions were highly sensitive to turbulence …

The Aerodynamics Of A Cornering Inverted Wing In Ground Effect, James Keogh, Graham Doig, Tracie J. Barber, Sammy Diasinos

Aerospace Engineering

For racing car configurations an inverted wing produces negative lift that allows increased levels of acceleration to be maintained through corners. Routine aerodynamic analysis, however, will typically be in the straight-line condition. A numerical analysis of the inverted T026 wing geometry through the curved path of a constant radius corner was conducted. The asymmetrical properties of the oncoming flow resulted in the introduction of a rolling and yawing moment along the span, as well as side-force. Yaw angle, flow curvature and a velocity gradient resulted in changes to the pressure distribution over the wing surface. Primary vortex behaviour was observed …

Autonomous Close Formation Flight Of Small Uavs Using Vision-Based Localization, Michael B. Darling

Master's Theses

As Unmanned Aerial Vehicles (UAVs) are integrated into the national airspace to comply with the 2012 Federal Aviation Administration Reauthorization Act, new civilian uses for robotic aircraft will come about in addition to the more obvious military applications. One particular area of interest for UAV development is the autonomous cooperative control of multiple UAVs. In this thesis, a decentralized leader-follower control strategy is designed, implemented, and tested from the follower’s perspective using vision-based localization.

The tasks of localization and control were carried out with separate processing hardware dedicated to each task. First, software was written to estimate the relative state …

Applied Mass Properties Identification Method To The Cal Poly's Spacecraft Simulator, Long H. Dam

Master's Theses

The Cal Poly Spacecraft Simulator is currently being developed for future testing and verifying theoretical control applications. This paper details the effort to balance the platform and remove undesired external torque from the system using System Identification technique developed by Patrick Healy. Since the relationship between the input and output of the system is linear, the least square method is proposed to identify the mass properties and location of center of mass of the system. The tests use four sine wave generators that are out of phase with different amplitudes as the inputs to excite various structural modes of the …

On The Growth Rate Of Turbulent Mixing Layers: A New Parametric Model, Jeffrey L. Freeman

Master's Theses

A new parametric model for the growth rate of turbulent mixing layers is proposed. A database of experimental and numerical mixing layer studies was extracted from the literature to support this effort. The domain of the model was limited to planar, spatial, nonreacting, free shear layers that were not affected by artificial mixing enhancement techniques. The model is split into two parts which were each tuned to optimally fit the database; equations for an incompressible growth rate were derived from the error function velocity profile, and a function for a compressibility factor was generalized from existing theory on the convective …

Flight And Stability Of A Laser Inertial Fusion Energy Target In The Drift Region Between Injection And The Reaction Chamber With Computational Fluid Dynamics, Tiffany Leilani Mitori

Master's Theses

A Laser Inertial Fusion Energy (LIFE) target’s flight through a low Reynolds number and high Mach number regime was analyzed with computational fluid dynamics software. This regime consisted of xenon gas at 1,050 K and approximately 6,670 Pa. Simulations with similar flow conditions were performed over a sphere and compared with experimental data and published correlations for validation purposes. Transient considerations of the developing flow around the target were explored. Simulations of the target at different velocities were used to determine correlations for the drag coefficient and Nusselt number as functions of the Reynolds number. Simulations with different target angles …

Development Of Safety Standards For Cubesat Propulsion Systems, Liam Jon Cheney

Master's Theses

The CubeSat community has begun to develop and implement propulsion systems. This movement represents a new capability which may satisfy mission needs such as orbital and constellation maintenance, formation flight, de-orbit, and even interplanetary travel. With the freedom and capability granted by propulsion systems, CubeSat providers must accept new responsibilities in proportion to the potential hazards that propulsion systems may present.

The Cal Poly CubeSat program publishes and maintains the CubeSat Design Specification (CDS). They wish to help the CubeSat community to safety and responsibly expand its capabilities to include propulsive designs. For this reason, the author embarked on the …

Study The Effects Of Core Orientation And Different Face Thicknesses On Mechanical Behavior Of Honeycomb Sandwich Structures Under Three Point Bending, Joshua M. Lister

Master's Theses

This study will present the Experimental, numerical and analytical characterizations of composite sandwich structures needed to optimize structure design. In this study, the effects of varying honeycomb core ribbon orientation and varying face sheet thickness’s have on the flexural behavior of honeycomb sandwich structures was investigated. Honeycomb sandwich panels were constructed using Hexcel 6367 A250-5H carbon fiber face sheets and Hexcel Nomex HRH-10-1/8-5 honeycomb cores. The mechanical properties of the constituent materials were discovered experimentally using ASTM standards and theoretical models using honeycomb mechanics and classical beam and plate theory are described. A failure mode map for loading under three …

Evolution Of Perturbations In Flow Field Mechanics, Samantha R. Bell, David Forliti, Nils Sedano, Kriss Vanderhyde

STAR Program Research Presentations

This project explores the stability analysis of a given flow field. Specifically, where the peak disturbance occurs in a flow as this is the disturbance that is most likely to occur. In rocket combustion, it is important to understand where the maximum disturbance occurs so that the mixing of fuel can be stabilized. The instabilities are the results of frequencies in the area surrounding the flow field. The linear stability governing equations are employed to better understand the disturbance. The governing equations for continuity and momentum in the x and y directions are used to form an equation for the …

Aerodynamic Design And Development Of The Sunswift Iv Solar Racing Car, Graham Doig, Chris Beves

Aerospace Engineering

The aerodynamic design and development of the University of New South Wales' ultra-low-drag solar-electric Sunswitt IV car is described, detailing the student-led design process from initial concept sketches to the completed vehicle. The body shape was established and relined over a period of six months in 2008-2009, almost entirely using computational fluid dynamics. The guiding philosophy was that predictable handling and drag minimization in challenging, changing wind conditions of the type commonly seen during the World Solar Challenge across Australia was preferable to high performance only on 'perfect' days. The car won its class in the 2009 and 2011 World …

Implications Of Compressibility Effects For Reynolds-Scaled Testing Of An Inverted Wing In Ground Effect, G. Doig, Tracie J. Barber, Sammy Diasinos

Aerospace Engineering

The influence of compressibility around an isolated inverted wing at a fixed Reynolds number was examined as relevant to the issue of wind tunnel scaling effects. Three-dimensional simulations were conducted for low ground clearances, at: full scale and a Mach number of 0.088, at 50% scale at Mach 0.176, and at 25% scale at Mach 0.352. As the scale was reduced, the increasing peak local Mach number between the wing and the ground resulted in a higher propensity of the flow to separate towards the trailing edge, and for incompressible or full-scale CFD to underestimate the lift and drag coefficients …

Investigation Into The Mitigation Of The Effects Of Uncertain Optical Degradation On An Interplanetary Solar Sail Mission Using A Single Model Update, Jordan Smiroldo

Master's Theses

The renewed academic interest in using solar sails as a source of spacecraft propulsion has been accompanied by a recent fervor of investigations into non-ideal and off-nominal sail performance considerations. One of the most influential considerations, uncertain optical degradation, has been shown to present significant trajectory design difficulties. This paper investigates the potential of using a mid-course degradation model update to mitigate the risk of missing the target destination in a sample 300 day Earth-Venus trajectory. Using a range of potential degradation profiles, it is shown that correcting in the first half of the mission is highly likely to result …

Analysis Of An Inflatable Gossamer Device To Efficiently De-Orbit Cubesats, Robert A. Hawkins Jr.

Master's Theses

There is an increased need for spacecraft to quickly and efficiently de-orbit themselves as the amount of debris in orbit around Earth grows. Defunct spacecraft pose a significant threat to the LEO environment due to their risk of fragmentation. If these spacecraft are de-orbited at the end of their useful life their risk to future spacecraft is greatly lessened. A proposed method of efficiently de-orbiting spacecraft is to use an inflatable thin-film envelope to increase the body's area to mass ratio and thusly shortening its orbital lifetime. The system and analysis presented in this project is sized for use on …

Adaptive Control Techniques For Transition-To-Hover Flight Of Fixed-Wing Uavs, Brian Decimo Marchini

Master's Theses

Fixed-wing unmanned aerial vehicles (UAVs) with the ability to hover combine the speed and endurance of traditional fixed-wing fight with the stable hovering and vertical takeoff and landing (VTOL) capabilities of helicopters and quadrotors. This combination of abilities can provide strategic advantages for UAV operators, especially when operating in urban environments where the airspace may be crowded with obstacles. Traditionally, fixed-wing UAVs with hovering capabilities had to be custom designed for specific payloads and missions, often requiring custom autopilots and unconventional airframe configurations. With recent government spending cuts, UAV operators like the military and law enforcement agencies have been urging …

Hollow Plume Mitigation Of A High-Efficiency Multistage Plasma Thruster, Scott Alan Mcgrail

Master's Theses

Since 2000, a relatively new electric thruster concept has been in research, development, and production at Thales Electron Devices in Germany. This High Efficiency Multistage Plasma Thruster, or HEMPT, has promising lifetime capabilities due to its plasma confinement system. However, the permanent magnet system that offers this and other benefits also creates a hollow plume, where ions are accelerated at angles rather than up the thruster centerline, causing a dip in ion current along the centerline. A laboratory model, built at JPL, was run at Cal Poly to characterize this plume shape and implement a shield to restore a conical …

Numerical Flow Field Analysis Of An Air Augmented Rocket Using The Axisymmetric Method Of Characteristics, Jeffrey Massman

Master's Theses

An Axisymmetric Rocket Ejector Simulation (ARES) was developed to numerically analyze various configurations of an air augmented rocket. Primary and secondary flow field visualizations are presented and performance predictions are tabulated. A parametric study on ejector geometry is obtained following a validation of the flow fields and performance values.

The primary flow is calculated using a quasi-2D, irrotational Method of Characteristics and the secondary flow is found using isentropic relations. Primary calculations begin at the throat and extend through the nozzle to the location of the first Mach Disk. Combustion properties are tabulated before analysis to allow for propellant property …

Remote/Autonomous Sentry Gun Platform, Angelo Gagliardi, Dante Gagliardi

Electrical Engineering

This senior project involves the complete system design and construction of a "Nerf" sentry gun to replace an armed guard. We aimed to develop a compact and highly mobile defense system that allows operational flexibility. The sentry gun can autonomously track and shoot at moving targets, while also allowing a user to remotely access and control the gun via computer. The mobility, hardiness, and functionality of this system allows a reliable replacement for human beings in harsh and hostile environments; ultimately sparing a life.

Mode I Fracture Toughness Of Eight-Harness-Satin Carbon Cloth Weaves For Co-Cured And Post-Bonded Laminates, Josh E. Smith

Master's Theses

Mode I interlaminar fracture of 3k 8-Harness-Satin Carbon cloth, with identical fill and weft yarns, pre-impregnated with Newport 307 resin was investigated through the DCB test (ASTM D5528). Crack propagations along both the fill and weft yarns were considered for both post-bonded (co-bonded) and co-cured laminates. A patent-pending delamination insertion method was compared to the standard Teflon film option to assess its applicability to mode I fracture testing. The Modified Beam Theory, Compliance Calibration method, and Modified Compliance Calibration method were used for comparative purposes for these investigations and to evaluate the validity of the proposed Equivalent Stiffness (EQS) method. …

Light Curve Generation For Satellites In Geostationary Orbits, Kimberly Andersen

Aerospace Engineering

This research were conducted at California Polytechnic State University San Luis Obispo throughout the Winter, Spring, and Fall quarters of 2013. The data presented in this paper was taken on the night of October 20, 2013 at the Cal Poly San Luis Obispo Astronomical Observatory and was reduced using IRAF software available on campus. This report describes the results of an observation of two bright XM geostationary satellites and the steps taken to get to those results. The average magnitude values of the XM-1 and XM-2 satellites were 13.753±0.007 and 14.015±0.007 respectively. The magnitude varied an average of 0.1 magnitudes …

Modification Of A Low Cost Vacuum Chamber For Use With An Electromagnetic Railgun, Jason M. Bertels

Aerospace Engineering

This report details the design and manufacture of modifications to a low cost vacuum chamber intended for railgun operations. These modifications intend to increase the functionality of the chamber and enable the modeling of high velocity impacts in a space. The original vacuum chamber was constructed primarily from polyvinyl chloride to meet the low cost design constraints, which limits pressures obtainable to the low vacuum region (760 Torr to 2 Torr). Modifications include construction of a space-saving storage rack, replacement of external door supports, installation of an internal guide rail, and installation of electrical feedthroughs.

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

Master's Theses

In the past, 2D CFD analysis of Circulation Control technology have shown poor comparison with experimental results. In Circulation Control experiments, typical results show a relationship between lift coefficient, CL, vs blowing momentum coefficient, Cμ. CFD analysis tend to over-predict values of CL due to gridding issues and/or turbulence model selection. This thesis attempted to address both issues by performing Richardson’s Extrpolation method to determine an acceptable mesh size and by using FLUENT’s 2-equation turbulence models. The experimental results and CAD geometry were obtained from Georgia Tech Research Institute for comparison with the CFD analysis.

The study showed that 3D …

Attitude Estimation For A Gravity Gradient Momentum Biased Nanosatellite, Arash Mehrparvar

Master's Theses

Attitude determination and estimation algorithms are developed and implemented in simulation for the Exocube satellite currently under development by PolySat at Cal Poly. A mission requirement of ±5˚ of attitude knowledge has been flowed down from the NASA Goddard developed payload, and this requirement is to be met with a basic sensor suite and the appropriate algorithms. The algorithms selected in this work are TRIAD and an Extended Kalman Filter, both of which are placed in a simulation structure along with models for orbit propagation, spacecraft kinematics and dynamics, and sensor and reference vector models. Errors inherent from sensors, orbit …

Qualitative Methods Used To Develop And Characterize The Circulation Control System On Cal Poly's Amelia, Eric N. Paciano

Master's Theses

The circulation control system onboard Cal Poly's Advanced Model for Extreme Lift and Improved Aeroacoustics was a critical component of a highly complex wind tunnel model produced in order to fulfill the requirements of a NASA Research Announcement awarded to David Marshall of the Aerospace Engineering Department. The model was based on a next generation, 150 passenger, regional, cruise efficient, short take-off and landing concept aircraft that achieved high lift through circulation control wings and over-the-wing mounted engines. The wind tunnel model was 10-ft in span, used turbine propulsion simulators, and had a functioning circulation control system driven from tunnel …

Mechanical Design Of Pird (Principal Investigator Rack Drawer) For Sofia, Hari Prasad Shetty Mr., Murali Krishna Kandlagunta Mrs., John Miles Mr., Zaheer Ali Mr.

STAR Program Research Presentations

SOFIA, the world’s largest airborne observatory with 2.5-meter diameter infrared telescope is equipped with 7 instruments: EXES, FIFI-LS, FLITECAM, FORCAST, GREAT, HAWC, and HIPO. Flying at altitudes between 39,000 and 45,000 feet, SOFIA avoids 99% of the atmospheric water vapor, records and analyzes the infrared radiation from the cosmos. SOFIA is able to observe the occultation of stars by solar system objects. By determining the size, compositions, and atmospheric structures of these objects, SOFIA can help answer the questions on creation and evolution of the universe, formation of the stars and planets, and nature of black hole at the center …

If It Isn’T Tested, It Doesn’T Work: Automated Verification Of Sofia Data Handling Software, Garrett Holthaus, Brett Stroozas, Zaheer Ali

STAR Program Research Presentations

This project involves writing code to automate the verification testing of the Data Handling Working Group (DHWG) software tools for the Stratospheric Observatory for Infrared Astronomy (SOFIA). The DHWG tools extract engineering data from SOFIA missions. Engineering data includes a variety of information on the operations and status of SOFIA systems during a flight, including computer network traffic, user commands, and images acquired from cameras mounted on the telescope assembly. It is important to review engineering data because this data can lead to the discovery of any problems or inefficiencies in SOFIA hardware and software. Analysis of engineering data can …

Design, Fabrication And Test Of An Operationally Responsive Aircraft With Niirs Evaluated Imager, Colin Burt

Master's Theses

Unmanned Aerial Systems (UAS) are a growing asset. Currently UAS are on the cutting edge with resources being spent developing the capabilities mostly for military use. This project is intended to create a system for non-defense customers. Specifically, the Operationally Responsive Aircraft (ORA) will appeal to academic institutions, individual consumers, future customers new to the UAS industry, as well as anybody trying to get airtime for custom sensors.

The system developed in this project utilizes dual aluminum external payload bays attached to a ParkZone Radian aircraft. Each external payload bay can contain approximately 500 $\text{cm}^3$, with a height and width …

Interaction Of A Shock Tube Exhaust Flow With A Non-Pre-Mixed Flame, Graham Doig, Zebulan Johnson, Rachel Mann

Aerospace Engineering

No abstract provided.

A Study Of The Collisional Evolution Of Orbital Debris In Geopotential Wells And Geo Disposal Orbits, Christina R. Diaz

Master's Theses

This thesis will present the effects of the orbital debris evolution in two key areas: the geosynchronous disposal orbit regime known as “graveyard” and the two geopotential wells found in 105◦ W and 75◦ E longitude bins. After developing a GEO specific orbit propagator for NASA Johnson Space Center’s Orbital Debris Of- fice, collisions were simulated throughout these regimes using a low velocity breakup model. This model considered the effects of perturbations particularly non-spherical Earth effects (specifically sectorial and zonal harmonics), lunar effects, third body effects and solar radiation pressure effects. The results show that CDPROP does well in simulating …

The Feasibility And Application Of Observing Small Leo Satellites With Amateur Telescopes, Brock Schmalzel

Master's Theses

This thesis demonstrates that any individual can provide relevant observational data to further research efforts within the Aerospace community, through the use of amateur telescopes. A Meade LX200 12 in. telescope and Lumenera Skynyx 2.0 camera were utilized to observe small LEO satellites, using a well-documented point-and-wait staring method. Over a period of three months, a total of 186 observation attempts were made resulting in 97 successful captures. From the gathered data, three possible aerospace applications were analyzed: validation of a satellite brightness prediction model, angles-only orbit determination including extended Kalman filtering, and temporal error growth in TLE-based orbit propagation. …