Alterations Of The Cal Poly Supersonic Wind Tunnel To Increase Accuracy And Prove The Absence Of Shockwaves, 2010 California Polytechnic State University, San Luis Obispo

#### 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 …

Conceptual Aircraft Hinge Moment Measurement System, 2010 California Polytechnic State University, San Luis Obispo

#### 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 …

Cal Poly Flight Test Platform For Instrument Development, 2010 California Polytechnic State University, San Luis Obispo

#### 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 …

Hybrid Rocket Motor, 2010 California Polytechnic State University, San Luis Obispo

#### 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 …

Analysis Of Curvature Effects On Boundary Layer Separation And Turbulence Model Accuracy For Circulation Control Applications, 2010 California Polytechnic State University, San Luis Obispo

#### 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, …

Assessment Of Carbon-Phenolic-In-Air Chemistry Models For Atmospheric Reentry, 2010 University of Michigan

#### Assessment Of Carbon-Phenolic-In-Air Chemistry Models For Atmospheric Reentry, Alexandre Martin, Iain D. Boyd

*Alexandre Martin*

Recent and future re-entry vehicle designs use ablative material as the main component of the heat shield of their thermal protection system. In order to properly predict the behavior of the vehicle, it is imperative to take into account the gases produced by the ablation process when modeling the reacting flow environment. In the case of charring ablators, where an inner resin is pyrolyzed at a relatively low temperature, the composition of the gas expelled in the boundary layer is complex and might lead to thermal chemical reactions that cannot be captured with simple flow chemistry models. In order to …

Mesh Tailoring For Strongly Coupled Computation Of Ablative Material In Nonequilibrium Hypersonic Flow, 2010 University of Michigan - Ann Arbor

#### Mesh Tailoring For Strongly Coupled Computation Of Ablative Material In Nonequilibrium Hypersonic Flow, Alexandre Martin, Iain D. Boyd

*Alexandre Martin*

A one-dimensional material response implicit solver with surface ablation and pyrolysis is strongly coupled to LeMANS, a CFD code for the simulation of weakly ionized hypersonic flows in thermo-chemical non-equilibrium. Using blowing wall boundary conditions and a moving mesh algorithm, the results of a strongly coupled solution of a sample re-entry problem are presented. Because of the requirement of a coupling scheme, an Arbitrary Lagrangian-Eulerian (ALE) approach is used to compute the flux, allowing the mesh to move as the surface ablates. However, as the shape of the vehicle changes, the shock location and geometry are also modified. Using the …

Analytic Confusion Matrix Bounds For Fault Detection And Isolation Using A Sum-Of-Squared-Residuals Approach, 2010 Cleveland State University

#### Analytic Confusion Matrix Bounds For Fault Detection And Isolation Using A Sum-Of-Squared-Residuals Approach, Daniel J. Simon, Donald L. Simon

*Electrical Engineering & Computer Science Faculty Publications*

Given a system which can fail in 1 of n different ways, a fault detection and isolation (FDI) algorithm uses sensor data to determine which fault is the most likely to have occurred. The effectiveness of an FDI algorithm can be quantified by a confusion matrix, also called a diagnosis probability matrix, which indicates the probability that each fault is isolated given that each fault has occurred. Confusion matrices are often generated with simulation data, particularly for complex systems. In this paper, we perform FDI using sum-of-squared residuals (SSRs). We assume that the sensor residuals are s-independent and Gaussian, which …

Development Of A Meshless Method To Solve Compressible Potential Flows, 2010 California Polytechnic State University, San Luis Obispo

#### Development Of A Meshless Method To Solve Compressible Potential Flows, Alejandro Ramos

*Master's Theses*

The utility of computational fluid dynamics (CFD) for solving problems of engineering interest has experienced rapid growth due to the improvements in both memory capacity and processing speed of computers. While the capability now exists for the solution of the Navier-Stokes equations about complex and complete aircraft configurations, the bottleneck within the process is the time consuming task of properly generating a mesh that can accurately solve the governing partial differential equations (PDEs). This thesis explored two numerical techniques that attempt to circumvent the difficulty associated with the meshing process by solving a simplified form of the continuity equation within …

Numerical Examination Of Flow Field Characteristics And Fabri Choking Of 2d Supersonic Ejectors, 2010 California Polytechnic State University, San Luis Obispo

#### Numerical Examination Of Flow Field Characteristics And Fabri Choking Of 2d Supersonic Ejectors, Brett G. Morham

*Master's Theses*

An automated computer simulation of the two-dimensional planar Cal Poly Supersonic Ejector test rig is developed. The purpose of the simulation is to identify the operating conditions which produce the saturated, Fabri choke and Fabri block aerodynamic flow patterns. The effect of primary to secondary stagnation pressure ratio on the efficiency of the ejector operation is measured using the entrainment ratio which is the secondary to primary mass flow ratio.

The primary flow of the ejector is supersonic and the secondary (entrained) stream enters the ejector at various velocities at or below Mach 1. The primary and secondary streams are …

Novel Inverse Airfoil Design Utilizing Parametric Equations, 2010 California Polytechnic State University, San Luis Obispo

#### Novel Inverse Airfoil Design Utilizing Parametric Equations, Kevin A. Lane

*Master's Theses*

The engineering problem of airfoil design has been of great theoretical interest for almost a century and has led to hundreds of papers written and dozens of methods developed over the years. This interest stems from the practical implications of airfoil design. Airfoil selection significantly influences the application's aerodynamic performance. Tailoring an airfoil profile to its specific application can have great performance advantages. This includes considerations of the lift and drag characteristics, pitching moment, volume for fuel and structure, maximum lift coefficient, stall characteristics, as well as off-design performance.

A common way to think about airfoil design is optimization, the …

A Three Dimensional Vortex Particle-Panel Code For Modeling Propeller-Airframe Interaction, 2010 California Polytechnic State University, San Luis Obispo

#### A Three Dimensional Vortex Particle-Panel Code For Modeling Propeller-Airframe Interaction, Jacob S. Calabretta

*Master's Theses*

Analysis of the aerodynamic effects of a propeller flowfield on bodies downstream of the propeller is a complex task. These interaction effects can have serious repercussions for many aspects of the vehicle, including drag changes resulting in larger power requirements, stability changes resulting in adjustments to stabilizer sizing, and lift changes requiring wing planform adjustments.

Historically it has been difficult to accurately account for these effects at any stage during the design process. More recently methods using Euler solvers have been developed that capture interference effects well, although they don't provide an ideal tool for early stages of aircraft design, …

Theoretical Models For Wall Injected Duct Flows, 2010 University of Tennessee Space Institute

#### Theoretical Models For Wall Injected Duct Flows, Tony Saad

*Doctoral Dissertations*

This dissertation is concerned with the mathematical modeling of the flow in a porous cylinder with a focus on applications to solid rocket motors. After discussing the historical development and major contributions to the understanding of wall injected flows, we present an inviscid rotational model for solid and hybrid rockets with arbitrary headwall injection. Then, we address the problem of pressure integration and find that for a given divergence free velocity field, unless the vorticity transport equation is identically satisfied, one cannot find an analytic expression for the pressure by direct integration of the Navier-Stokes equations. This is followed by …

A Novel Telescopic Boom Deployment System For Use In Upper Atmosphere Research, 2010 Technological University Dublin

#### A Novel Telescopic Boom Deployment System For Use In Upper Atmosphere Research, Mark Wylie, Paul Duffy, Dinesh Vather, Johnalan Keegan, Stephen Curran

*Conference Papers*

Typical measurement probe deployment systems on sounding rockets employ hinged booms which extend the probes away from the rocket. This configuration often has a significant mass and may require a considerable amount of the rocket’s valuable payload volume. In an effort to reduce both mass and volume, the DIT Space Research Group have designed a light weight carbon fibre telescopic boom system, compatible with measurement probes commonly used in upper atmosphere research. Our design has been selected to be tested on a suborbital space flight onboard the REXUS 9 sounding rocket in March 2011. The purpose of this test is …

An Empirical Model Of Thermal Updrafts Using Data Obtained From A Manned Glider, 2010 University of Tennessee - Knoxville

#### An Empirical Model Of Thermal Updrafts Using Data Obtained From A Manned Glider, Christopher E. Childress

*Masters Theses*

Various methods have been used, including airborne radars, LIDAR, observation of flying birds, towers, tethered balloons, and aircraft to gain both a qualitative and quantitative representation of how heat and moisture are transported to higher altitudes and grow the boundary or mixing layer by thermal updrafts. This paper builds upon that research using an instrumented glider to determine the structure and build a mathematical model of thermals in a desert environment. During these flights, it was discovered that the traditional view of a thermal as a singular rising plume of air did not sufficiently explain what was being observed, but …

Inter Spem Et Metum, Fiat Lux, 2010 Rhode Island College

#### Inter Spem Et Metum, Fiat Lux, Michael A. Mota

*Honors Projects Overview*

Explores the design and development of a simple, 3D flight simulator. The resulting application allows users to pilot an abstract human avatar and to create free-hand strokes and physically-based explosions onto the environment through a ball discharge meta-game feature. Uses the C++ language, and the ancillary programming API libraries, OpenGL, GLEW, and Win32.

Stability Of Fully Nonlinear Stokes Waves On Deep Water: Part 1. Perturbation Theory, 2010 Embry-Riddle Aeronautical University

#### Stability Of Fully Nonlinear Stokes Waves On Deep Water: Part 1. Perturbation Theory, Shahrdad Sajjadi, David L. Ross

*Publications*

We consider a full set of harmonics for the Stokes wave in deep water in the absence of viscosity, and examine the role that higher harmonics play in modifying the classical Benjamin-Feir instability. Using a representation of the wave coefficients due to Wilton, a perturbation analysis shows that the Stokes wave may become unbounded due to interactions between the *N ^{th}* harmonic of the primary wave train and a set of harmonics of a disturbance. If the frequency of the

*n*harmonic is denoted

^{th}*Ꙍ*

_{n}=

*Ꙍ(1*± ꭉ) then instability will occur if

√2 k n^{n …}

High Order Finite Elements For Lagrangian Computational Fluid Dynamics, 2010 California Polytechnic State University, San Luis Obispo

#### High Order Finite Elements For Lagrangian Computational Fluid Dynamics, Truman Everett Ellis

*Master's Theses*

A general finite element method is presented to solve the Euler equations in a Lagrangian reference frame. This FEM framework allows for separate arbitrarily high order representation of kinematic and thermodynamic variables. An accompanying hydrodynamics code written in Matlab is presented as a test-bed to experiment with various basis function choices. A wide range of basis function pairs are postulated and a few choices are developed further, including the bi-quadratic Q2-Q1d and Q2-Q2d elements. These are compared with a corresponding pair of low order bi-linear elements, traditional Q1-Q0 and sub-zonal pressure Q1-Q1d. Several test problems are considered including static convergence …

Assessing The V2-F Turbulence Models For Circulation Control Applications, 2010 California Polytechnic State University, San Luis Obispo

#### Assessing The V2-F Turbulence Models For Circulation Control Applications, Travis M. Storm

*Master's Theses*

In recent years, airports have experienced increasing airport congestion, partially due to the hub-and-spoke model on which airline operations are based. Current airline operations utilize large airports, focusing traffic to a small number of airports. One way to relieve such congestion is to transition to a more accessible and efficient point-to-point operation, which utilizes a large web of smaller airports. This expansion to regional airports propagates the need for next-generation low-noise aircraft with short take-off and landing capabilities. NASA has attacked this problem with a high-lift, low-noise concept dubbed the Cruise Efficient Short Take-Off and Landing (CESTOL) aircraft. The goal …

Cfd Analysis Of Experimental Wing And Winglet For Falconlaunch 8 And The Exfit Program, 2010 Air Force Institute of Technology

#### Cfd Analysis Of Experimental Wing And Winglet For Falconlaunch 8 And The Exfit Program, Benjamin P. Switzer

*Theses and Dissertations*

Reusable launch vehicles have many benefits over their expendable counterparts. These benefits range from cost reductions to increased functionality of the vehicles. Further research is required in the development of the technology necessary for reusable launch vehicles to come to fruition. The Air Force Institute of Technology’s future involvement in the ExFIT program will entail designing and testing of a new wing tip mounted vertical stabilizer in the hypersonic regime. One proposed venue for experimentation is to utilize the United States Air Force Academy’s FalconLAUNCH Program which annually designs, builds, and launches a sounding rocket capable of reaching hypersonic speeds. …