Aerospace Engineering Commons^™

Compressor Performance Map Generation And Testing Per Sae J1723, Jeffrey Lee Freeman

Aerospace Engineering

A MATLAB program was written to plot compressor performance maps for a set of test data that was collected in accordance with SAE J1723 at Vortech Engineering, Inc. Paxton Automotive Corp.'s N2500 supercharger was used as a case example for the program, which was carried through from test stand installation to finalized compressor performance map. A sequence was also developed to interpolate the efficiency of the compressor for a given operational setting. The program was shown to be a great improvement from the previously applied technique for accomplishing the same tasks; it is more accurate in plotting the given data, …

Dealing With Contaminated Runways, Nihad E. Daidzic

Aviation Department Publications

No abstract provided.

Effect Of Thermally Induced Deformation In A Supersonic Combustion Facility, Aditya Ajit Gupte

Master's Theses - Daytona Beach

Nastran and ANSYS finite element analysis (FEA) and Wind-US computational fluid dynamics (CFD) solvers are used to simulate the effect of thermal deformation on the reacting flow developing within the University of Virginia (UVa) Supersonic Combustion Facility (SCF). A detailed thermal-structural model is developed to resolve the temperature distribution and the resulting structural deformation taking place within the scramjet engine flowpath. The predicted thermal deformation is used to refine the CFD model and produce a new set of results for direct comparison with experiment during both ramjet and scramjet modes of operation. Improved agreement between CFD and experiment is afforded …

Validation Of Proposed Metrics For Two-Body Abrasion Scratch Test Analysis Standards, Ryan L. Kobrick, David M. Klaus, Kenneth W. Street

Publications

The objective of this work was to evaluate a set of standardized metrics proposed for characterizing a surface that has been scratched from a two-body abrasion test. This is achieved by defining a new abrasion region termed “Zone of Interaction” (ZOI). The ZOI describes the full surface profile of all peaks and valleys, rather than just measuring a scratch width as currently defined by the ASTM G 171 Standard. The ZOI has been found to be at least twice the size of a standard width measurement, in some cases considerably greater, indicating that at least half of the disturbed surface …

Study Of Emission Turbulence-Radiation Interaction In Hypersonic Boundary Layers, L. (Lian) Duan, M. P. Martín, I. Sohn, D. A. Levin, M. F. Modest

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Direct numerical simulations are conducted to study the effects of emission turbulence-radiation interaction in hypersonic turbulent boundary layers, representative of the Orion Crew Exploration Vehicle at peak-heating condition during reentry. A nondimensional governing parameter to measure the significance of emission turbulence-radiation interaction is proposed, and the direct numerical simulation fields with and without emission coupling are used to assess emission turbulence-radiation interaction. Both the uncoupled and coupled results show that there is no sizable interaction between turbulence and emission at the hypersonic environment under investigation. An explanation of why the intensity of emission turbulence-radiation interaction in the hypersonic boundary layer …

Nanostructured Substrate With Nanoparticles Fabricated By Femtosecond Laser For Surface-Enhanced Raman Scattering, Yukun Han, Zhi Liang, Huilai Sun, Hai Xiao, Hai-Lung Tsai

Electrical and Computer Engineering Faculty Research & Creative Works

A Simple and Fast Method to Fabricate Nanostructured Substrates with Silver Nanoparticles over a Large Area for Surface-Enhanced Raman Scattering (SERS) is Reported. the Method Involves Two Steps: (1) Dip the Substrate into a Silver Nitrate Solution for a Few Minutes, Remove the Substrate from the Solution, and Then Air Dry and (2) Process the Silver Nitrate Coated Substrate by Femtosecond (Fs) Laser Pulses in Air. the Second Step Can Create Silver Nanoparticles Distributed on the Nanostructured Surface of the Substrate by the Photoreduction of Fs Multiphoton Effects. This Study Demonstrates that an Enhancement Factor (EF) Greater Than 5x105, Measured …

The Future Of Cubesats: Presentation To The Iaa, Ben Malphrus

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by Professor Bob Twiggs titled "The Future of CubeSats: Presentation to the IAA" from January 28, 2011.

Flying Uav’S In Iraq, Stephen Rayleigh

ERAU Prescott Aviation History Program

Unmanned Aerial Vehicles, or UAV’s, are a growing reality and an important new weapon for today’s military. Hear what it was like to fly the RQ-7B “Shadow” UAV during Operation Iraqi Freedom from Stephen Rayleigh who spent a year in Iraq and has more than 1,000 hours experience flying them.

Part 2: Preparation For Wind Tunnel Model Testing And Verification Of Cal Poly’S Amelia 10 Foot Span Hybrid Wing-Body Low Noise Cestol Aircraft, Kristina Jameson, David D. Marshall, Robert Ehrmann, Eric Paciano, Robert J. Englar, William C. Horne

Aerospace Engineering

A collaboration between California Polytechnic Corporation with Georgia Tech Research Institute (GTRI) and DHC Engineering worked on a NASA NRA to develop predictive capabilities for the design and performance of Cruise Efficient, Short Take-Off and Landing (CESTOL) subsonic aircraft. The focus of this work presented in this paper gives details of a large scale wind tunnel effort to validate predictive capabilities for this NRA for aerodynamic and acoustic performance during takeoff and landing. The model, Advanced Model for Extreme Lift and Improved Aeroacoustics (AMELIA), was designed as a 100 passenger, N+2 generation, regional, cruise efficient short takeoff and land (CESTOL) …

Investigation Of The Unsteady Behavior Of A Circulation Control Wing Using Computational Fluid Dynamics, Jonathon A. Lichtwardt, David D. Marshall

Aerospace Engineering

This paper details the results of an investigation into the unsteady behavior of a circulation control wing using computational fluid dynamics. Oscillations in the lift coefficient of up to 10% are observed for steady state simulations. An investigation into the source of the unsteadiness is underway, and the results to date are presented. It is shown that the periodic oscillations are independent of the above the wing mounted engine effects on the cruise efficient short take-off and landing aircraft. The oscillations are also a viscous phenomenon that does not dampen as the solution marches through steady state. It is proposed …

Improved Meshing Technique For The Engine Exhaust Of An Over-The-Wing Engine And Circulation Control Wing Configuration, John Pham, David D. Marshall

Aerospace Engineering

This paper details the results of ongoing efforts to improve upon the meshing techniques required to produce accurate RANS CFD solutions for attached and separated flows for a Circulation Control aircraft. Work, thus far, under the current NASA Research Announcement (NRA) project has revolved around an unstructured near-body volume mesh due to its robustness for complicated geometries. However, it has been found that this technique does a poor job capturing detailed flow features such as the boundary layer, shear layer, and wake of large velocity-gradient regions. Its hindrance is primarily due to the limitations of current computational resources, thus new …

A Meshless Finite Difference Scheme For Compressible Potential Flows, Alejandro Ramos, Robert A. Mcdonald

Aerospace Engineering

A meshless solution algorithm for the full potential equation has been developed by applying the principles of the Taylor Least Squares (TLS) method. This method allows for a PDE to be discretized on a local cloud of scattered nodes without the need of connectivity data. The process for discretizing the full potential equation within a meshless framework is outlined along with a novel Hermite TLS technique for enforcement of Neumann boundary conditions. Several two-dimensional test cases were solved that compare well with analytical and benchmark solutions. The first test case solved for the subcritical compressible flow over a circular cylinder …

Part 1: The Wind Tunnel Model Design And Fabrication Of Cal Poly's Amelia 10 Foot Span Hybrid Wing-Body Low Noise Cestol Aircraft, Kristina K. Jameson, David D. Marshall, Rory Golden, Eric Paciano, Robert J. Englar, Richard J. Gaeta, Jay Paterson, Dave Mason

Aerospace Engineering

A collaboration between California Polytechnic Corporation with Georgia Tech Research Institute (GTRI) and DHC Engineering worked on a NASA NRA to develop predictive capabilities for the design and performance of Cruise Efficient, Short Take-Off and Landing (CESTOL) subsonic aircraft. In addition, a large scale wind tunnel effort to validate these predictive capabilities for this NRA for aerodynamic and acoustic performance 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, cruise efficient short takeoff and land (CESTOL) airliner with hybrid blended wing-body with …

A Scientific Software Verification Library Based On The Method Of Manufactured Solutions, David D. Marshall

Aerospace Engineering

A software library, avali, is being developed in the C++ programming language that applies the Method of Manufactured Solutions (MMS) to a variety of partial differential equation (PDE) problems. This library will allow researchers to utilize MMS as a software verification process without developing significant amounts of testing code. The library is split into 3 components: solution classes which can be used as manufactured solutions to PDE problems; PDE problem classes which represent specific types of PDEs to be solved (such as linear convection-diffusion equation or Poisson's equation); and post-processing classes that collect the convergence information and can perform various …

Terminal Guidance Of Autonomous Parafoils In High Wind-To-Airspeed Ratios, Nathan Slegers, O A. Yakimenko

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Autonomous precision placement of parafoils is challenging because of their limited control authority and sensitivity to winds. In particular, when wind speed is near the airspeed, guidance is further complicated by the parafoils inability to penetrate the wind. This article specifically addresses the terminal phase and develops an approach for generating optimal trajectories in real-time based on the inverse dynamics in the virtual domain. The method results in efficient solution of a two-point boundary-value problem using only a single optimization parameter allowing the trajectory to be generated at a high rate, mitigating effects of the unknown winds. It is shown …

Tethered Aerostat Modeling Using An Efficient Recursive Rigid-Body Dynamics Approach, Brad Hembree, Nathan Slegers

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

A tethered aerostat model is developed using a computationally efficient recursive tether model. The recursive rigid-body tether model results in unconstrained ordinary differential equations and maintains much of the simplicity of simple lumped-mass tether models, while avoiding numerical difficulties associated with using many stiff elastic elements with low mass. Further efficiency is achieved by treating each tether link as a body of revolution and assuming that tether spin is negligible to the dynamics. The tether is attached to a six-degree-of-freedom aerostat model using a single viscoelastic element. The final recursive tethered aerostat model is well suited for a variety of …

Get Away Special: Microgravity Research Team, Getaway Special Team

Education and Outreach

No abstract provided.

Report For 2011 Urco Funded Experiment: Development Of Optimal Bubble-Seeding Microheaters To Study Nucleate Boiling Heat Transfer In Microgravity, Ryan Martineau

Reports and Proposals

No abstract provided.

Space Trajectories Optimization Using Variable-Chromosome-Length Genetic Algorithms, Ahmed H. Gad

Dissertations, Master's Theses and Master's Reports - Open

The problem of optimal design of a multi-gravity-assist space trajectories, with free number of deep space maneuvers (MGADSM) poses multi-modal cost functions. In the general form of the problem, the number of design variables is solution dependent. To handle global optimization problems where the number of design variables varies from one solution to another, two novel genetic-based techniques are introduced: hidden genes genetic algorithm (HGGA) and dynamic-size multiple population genetic algorithm (DSMPGA).

In HGGA, a fixed length for the design variables is assigned for all solutions. Independent variables of each solution are divided into effective and ineffective (hidden) genes. Hidden …

Influence Of Initial Mean Helicity On Homogeneous Turbulent Shear Flow, Frank G. Jacobitz, Kai Schneider, Wouter J. T. Bos, Marie Farge

School of Engineering: Faculty Scholarship

Helicity statistics are studied in homogeneous turbulent shear flow. Initial mean helicity is imposed on an isotropic turbulence field using a decomposition of the flow into complex-valued helical waves. The initial decay of the turbulent kinetic energy is weakened in the presence of strong mean helicity, consistent with an analytic analysis of the spectral tensor of velocity correlations. While exponential growth of the mean turbulent kinetic energy is obtained, the mean helicity decays. Probability distribution functions (PDFs) of helicity are skewed and show that the imposed mean helicity prevails throughout the simulations. A wavelet-based scale-dependent analysis shows a trend to …