Engineering Commons^™

Subwoofer Frequency Response Optimization By Means Of Active Control, Luis Dominguez

Aerospace Engineering

Most subwoofer systems have difficulties producing frequencies in the low end of the hearing spectrum due to the added power requirements and instabilities. Active controls can transform the audio signal without changing physical characteristics and ultimately generating a more impressive audio system. A Linkwitz transform crossover was implemented to extend the low end frequency response of a sealed enclosure. A graphical user interface in MATLAB was written to aid in selection of components, driver and enclosure volume. The circuit board was built and integrated with a home theater system inside of a couch and tested with a Real Time Analyzer. …

Modeling And Preliminary Finite Element Analysis On The Spun Structure For The Cpintersep Project, Jason Carpenter, Kelly Cheng, Jeffrey Ma, Richard Pelham, Kevin Povey

Aerospace Engineering

This paper details the process of modeling and importing the model into FEA for the spun structure of the BS376 spacecraft. Engineering drawings were converted into 3D models using Pro/Engineer and then imported and into Patran for pre-processing of a Finite Element Model. To verify the Finite Element Model, several test cases were set up and solved using Nastran solver. Our simple load cases were found to be in congruence with analytical solution methods validating the finite element model.

Hot Air Balloon Navigation, Dustin Blackwell

Aerospace Engineering

This report describes a program used for navigating a hot air balloon. The program, Balloon_Trip, was written using MATLAB and gives a flight path to follow from a start position to an end position. Balloon_Trip calculates the flight path by taking in wind conditions and then flying through these different winds so as to steer the hot air balloon. The program calculates the flight path by taking into consideration at all times how the wind will propel the balloon while it is rising or falling in elevation. It then takes the most direct and least complicated, if not fastest, …

Aerodynamics Of A Supersonic Projectile In Proximity To A Solid Surface, Graham Doig, Tracie Barber, Eddie Leonardi, Andrew J. Neely, Harald Kleine

Aerospace Engineering

Flow around a Mach 2.4 NATO 5.56 mm projectile in close proximity to a ground plane was investigated using computational fluid dynamics for a direct numerical reproduction of live-range experiments. The numerical approach was validated against both the live-range tests and subsequent wind-tunnel experiments. A nonspinning half-model and a full, spinning projectile were examined to clarify the influence of rotation. Multiple ground clearances were tested to obtain clear trends in changes to the aerodynamic coefficients, and the three-dimensional propagation and reflection of the shock waves were considered in detail. The behavior of the flow in the near wake was also …

Design And Wind Tunnel Testing Of Cal Poly's Amelia 10 Foot Span Hybrid Wing-Body Low Noise Cestol Aircraft, Kristina K. Jameson, David D. Marshall, Robert Ehrmann, Eric Paciano, Rory Golden, Dave Mason

Aerospace Engineering

California Polytechnic Corporation, Georgia Tech Research Institute (GTRI), and DHC Engineering collaborated on a NASA NRA to develop and validate predictive capabilities for the design and performance of Cruise Efficient, Short TakeOff and Landing (CESTOL) subsonic aircraft. In addition, a large scale wind tunnel effort to validate predictive capabilities for aerodynamic performance and noise during takeoff and landing has been undertaken.

The model, Advanced Model for Extreme Lift and Improved Aeroacoustics (AMELIA), was designed as a 100 passenger, N+2 generation, regional, CESTOL airliner with hybrid blended wingbody with circulation control. The model design was focused on fuelsavings and noise goals …

Mission Performance As Point Performance, Robert A. Mcdonald

Aerospace Engineering

The cruise or loiter performance of an aircraft is intimately tied to its wing loading (W/S) and its thrust to weight ratio (T/W). Paradoxically, mission performance is often not considered when these fundamental aircraft parameters are determined in conceptual design. In this research, the traditional constraint diagram is extended to include contours of range parameter. This point performance metric represents the mission performance capability of the aircraft without sizing the aircraft to a particular mission. This gives the designer an immediate and intuitive understanding of the tradeoff between the point and mission performance of the aircraft. This improved constraint diagram …

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 …

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 …

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 …

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.

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 …

Matlab® Gui Visualization Of Classical Orbital Elements, Nancy Teresa Cabrera

Aerospace Engineering

The classical orbital elements of an orbit are eccentricity, angular momentum, inclination, right ascension of ascending node, true anomaly, and argument of perigee. These six parameters define an orbit. Using MATLAB® to model a satellite orbiting Earth in three dimensions, a graphical user interface was created to allow a user to manipulate the orbital elements to desired quantities. In doing so, each parameter’s impact on the orbit is visually displayed. This furthers the understanding of how the parameters are linked to the orbit. When the interface is first opened, the default circular orbit has a range of 20,000 kilometers, an …

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 …

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, …

Rv-7 N675cp Lean Versus Rich Fuel Mixture Aircraft Performance, Edward Spenser Burgos, William Beaman Howe

Aerospace Engineering

The purpose of this experiment was to compare the effects of flying with lean mixture versus rich mixture on aircraft performance. This was done by taking data in the RV-7 N675CP aircraft, RV-7A base aircraft that was built by students at California Polytechnic State University of San Luis Obispo. The RV-7 N675CP contains a Lycoming O-360-A 180 HP engine and fully automated flight data acquisition system. Test flight data indicates the aircraft consumes less fuel, has greater engine exhaust gas temperature (EGT), and possibly increases airspeed with a lean fuel mixture.

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

Aerospace Engineering

No abstract provided.

Blended Wing Body Form Factor Code And Model Center Integration, Simone (Simo) Alberti

Aerospace Engineering

This senior project investigated a method of calculating the form factor of an arbitrarily shaped wing, such as a blended wing body, from its pressure coefficient distribution. A Matlab script was coded and integrated into an existing Model Center tool for blended wing bodies. Model Center allows a VSP model to be analyzed with PMARC, a panel code, to determine the pressure distribution over a wing. The Matlab code can then calculate the form factor and critical Mach number. It was found that the code can accurately model simple planar wings, validated against empirical equations, and is robust for blended …

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 …

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 …

Valveless Pulsejet Engine, Cory William Kerr, James Robert Reynolds

Aerospace Engineering

The goal of this project is to build a valveless pulsejet based on the Lady Anne model, known as the Focused Wave Engine VIII Twin Stack. This project has two main goals. The first goal is to design and build the valveless pulsejet. This includes machine work on stainless steel to build the engine, as well as modifying copper tubes to serve as a fuel injection system. The second goal is to build a test stand that allows for accurate data collection of the total thrust being produced by the engine and acts as a fuel injection and ignition system. …

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 …

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 …

Non-Explosive Actuator Simulator, Bryan Costanza

Aerospace Engineering

The CubeSat group at California Polytechnic State University, San Luis Obispo discovered the need for a new piece of ground test equipment. Previous testing of the non-explosive actuator has been very expensive and is not repeatable; two undesirable traits. The analysis of the fuse as well as the design and test of the simulator concept and final article is discussed. The simulator has already seen real use and its entire build and operation cost is much less than the cost of one test of the actual hardware. Performance of the simulator based on burn time and reset time is acceptable …

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.

Design, Fabrication, Structural Testing, And Numerical Analysis Of A Small Scale Composite Wing, Jacob David Gaunt, Juan Carlos Flores, Vincent Andrew Perry

Aerospace Engineering

A small scale composite wing based on a design found on an experimental aircraft was designed, constructed, and tested dynamically and statically. The wing was constructed similarly to an experimental aircraft wing. The performed static test was intended to produce pure bending. Strain gages were used to measure strains on the wing structure. The strains were converted to stresses to aid in analysis. The static test results suggested that the wing was actually under torsion. Four structural modes were found from the static test. A finite element analysis model was made to compare experimental results to numerical analytical results. The …

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 …

Delamination Of Sandwich Composites, Richard Anthony Davis

Aerospace Engineering

The use of shear keys to help stop or inhibit the face-sheet core delamination of sandwich composite beams under monotonic loading was analyzed in Cal Poly’s structural design lab. The composite beams were treated with the same boundary conditions as the ASTM D5528 double cantilever beam bending in which both faces of the beam remain free; one of the faces would have a debonded side and the other would not. An aluminum tab is attached to the top of the specimens and the load is applied there. Each specimen has piezoelectric sensors that are utilized in the detection of delamination …

Experimental Development Of Compressor And Turbine Performance Maps For Turbomachinery, Michael W. Green

Aerospace Engineering

Turbomachinery performance maps are used to reveal the on and off design performance of compressors and turbines. These maps plot the component’s pressure ratio versus the corrected flow rate for multiple engine rotor speeds. In this experiment, a Boeing T50-BO-8A converted turbojet engine was operated at a wide variety of rotor speeds with orifice plates of different sizes to vary the flow rate. The corrected flow rate through the turbojet ranged from 1.32 to 2.55 lb/s. The pressure ratios for the compressor and turbine ranged from 2.0 to 4.3 and from 1.7 to 4.3, respectively. The resulting performance maps showed …

Compression Testing Of Composite Laminated Foam Under Thermal Loading And With Central Holes, Dominic Surano, Jonathan Russo, Daniel Leighton

Aerospace Engineering

A study was conducted to investigate the effect of heat on composite sandwich plates, fabricated with the vacuum resin infusion process, with center holes of varying diameters. The study involved conventional notched specimens and notched specimens with shear keys, both of which were subjected to monotonic inplane compression loading. Hole diameter was be varied from one to four inches in one inch increments. Loading rate was applied using the Instron machine at one millimeter per minute. The diameter of the shear key around the holes varied from one inch to four inches in one inch increments. The specimens were placed …

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 …