Engineering Commons^™

Modular Multi-Stage Axial Compressor Design, Christopher S. Hemerly

Master's Theses - Daytona Beach

Increasingly, companies are becoming more interested in reducing cost. Recent studies indicate that up to 80% of the Lifecycle costs (LCC) has been embedded in the engine's DNA at the end of the development and design phase. One concept to aid in the cost reduction is the modular design of expensive and development-intensive components, such as multi-stage axial compressors. It is the objective of this approach to utilize a "core" module in all the compressors, thus maximizing commonality and minimizing all relevant development, design, manufacture, procurement, and service costs; these reductions in cost are projected to increase affordability by five-fold. …

Numerical Simulation Of Uva Ramjet/Scramjet Hypersonic Engine With Hydrogen-Air Combustion Using Wind-Us, Vishal Anand Bhagwandin

Master's Theses - Daytona Beach

The internal flowpath of University of Virginia's Mach 5, direct-connect, dual-mode scramjet engine was simulated using Wind-US, a density-based Reynolds-Averaged Navier-Stokes flow solver. Detailed flowfield simulation results are directly compared to experimental data to evaluate the accuracy of the numerical model and to provide insight into the flowfield behavior. Four hydrogen-air reaction mechanisms were initially assessed using the Burrows-Kurkov case. An Evans-Schexnayder, 7-specie, 8-reaction set with third body efficiencies was then selected for the scramjet simulations. The scramjet simulations included one fuel-off case and two reacting cases with different equivalence ratios, all with clean, non-vitiated air supply. The strong sensitivity …

Study Of The Influence Of Nacelle And Pylon On Aerodynamics Of A New Vu Design, Romain Larose

Master's Theses - Daytona Beach

The purpose of this thesis was to illustrate the influence of the nacelle and pylon on aerodynamics of a new Very Light Jet design, using Computational Fluid Dynamics.

The objective of the first phase was to repair the existing CATIA model in order to facilitate the meshing process.

The second and third phase was to create two meshes: a mesh for the complete model (aircraft with nacelle and pylon), and a second for the aircraft alone.

The two problems have been solved at cruise conditions using Navier-Stokes equations with a second order accuracy.

The model complying with theory, the results …

Design And Numerical Evaluation Of A Counter- Rotating Compressor In The Absence Of Boundary Layer Control: Part I, Naiara Petralanda

Master's Theses - Daytona Beach

The purpose of this thesis was to design and evaluate a three stage counter-rotating compressor that employed well established design principles and technologies using a phased approach. The objective of the first phase was to generate the preliminary annulus shape and estimate the major parameters by modeling the flow as inviscid and time independent. The second and third phases refined the design approximating the flow using Euler's equations and the Navier-Stokes equations respectively.

The performance predictions decreased as the design move forward and more accurate flow and loss models were used. The final three dimensional analysis, which was limited to …

Modeling And Parameter Estimation Of Spacecraft Lateral Fuel Slosh, Yadira Rodriguez Chatman

Master's Theses - Daytona Beach

Predicting the effect of fuel slosh on spacecraft and launch vehicle attitude control systems has been a very important and challenging task and has been the subject of considerable research over the past years. Analytic determination of the slosh analog parameters has been met with mixed success and is made more difficult by the introduction of propellant management devices such as elastomeric diaphragms. The experimental set-up in this research incorporates a diaphragm in a simulated spacecraft fuel tank subjected to lateral slosh behavior. This research focuses on the parameter estimation of a SimMechanics model of the simulated spacecraft propellant tank …

Modeling, Analysis And Testing Of A Semi-Active Control System For Landing Gear Applications, David James Majko

Master's Theses - Daytona Beach

There have been several recent studies on the potential benefits of controllable dampers. Controllable dampers can use a fluid with controllable properties, such as Magneto - Rheological fluid (MR fluid), or control the damping force by changing orifice size. For this project, controllable dampers were created using MR fluid. When exposed to a magnetic fluid, the viscosity of MR fluid can change significantly. By replacing the standard damper oil in an aircraft landing gear and exposing the system to an appropriate magnetic field, the damping coefficients of the system can be changed almost instantaneously to accommodate nearly any situation. This …

Application Of Kalman Filtering To Real-Time Flight Regime Recognition Algorithms In A Helicopter Health And Usage Monitoring System, Rachel Elizabeth Rajnicek

Master's Theses - Daytona Beach

The purpose of this study is the application of Kalman filters to real-time Flight Regime Recognition (FRR) algorithms to identify the regime flown and observe transitions between flight regimes. Rotor fault identification, a technique that is somewhat similar to flight regime recognition, successfully used Kalman filters to determine fault types and damage locations. Recently developed FRR algorithms successfully applied Hidden Markov Models, which are similar to Kalman filters. The selected regime set for this study derives from a study performed by Bell Helicopter Textron, Inc. The selected parameter set for this study is modified from the Schweizer 300 Flight Test …

The Analysis Of Flight Operational Quality Assurance (Foqa) Data: Exploration Of A Proposed List Of Improved Safety Parameters, Giorge Marlon Lopes Tsuruta

Master's Theses - Daytona Beach

Several FOQA parameters that could enhance air carrier safety have not been recorded and/or analyzed. Airlines have traditionally chosen a limited number of parameters for analysis (thousands have been available for recording). No study in the U.S. had addressed FOQA parameters, leading to an exploratory mixed methods study. A conference call comprising FOQA industry experts was planned and completed to (a increase researcher knowledge and (b) discuss a list of improved safety FOQA parameters. A questionnaire, derived from the suggested list, was electronically sent to 40 FOQA professionals. The respondents represented 75% of the airlines with an FAA-approved FOQA program. …

Using Ansys Workbench Computer Environment In Turbomachinery Design Process, Patricia Lynn Bowlds

Master's Theses - Daytona Beach

The main focus of designing turbomachinery is to analyze and optimize the aerodynamic efficiency and structural integrity of the machine. The preferred way to perform aerodynamic and structural analysis is to connect the analyses and shorten the analysis time as much as possible. ANSYS, Inc. provides a comprehensive approach to model fluid structure interaction phenomenon in turbomachinery within the ANSYS Workbench environment. This environment combines a number of software components that conduct blade design, fluid dynamic and structural analyses, and pre- and post-processing including mesh generation and overall performance estimation.

The focus of this study is to apply the ANSYS …

Development, Verification, And Future Applications Of A 3-Dof Entry And Descent Simulation Tool, Shaun Deacon

Master's Theses - Daytona Beach

With any space related mission, the unknown effects are often some of the most important design considerations. These effects must be accounted for in some fashion, and often lead to mission elements being centered around gathering information on the unknown.

It is the purpose of this research to develop and test a tool for simulation of entry, descent, and landing, (EDL) and to present a brief analysis of possible dispersion patterns related to autonomous radiosonde deployment on the surface of Mars.

The EDL simulation tool is written in Matlab. The aerodynamic information used by the tool is obtained with the …

An Investigation Of Classical Panel Stiffener Buckling Methods For Modern Airframe Applications, Ryan Timothy Holt

Master's Theses - Daytona Beach

Classical methods for buckling assessment of aircraft panels reinforced by bulb-stiffened flanges differ regarding symmetric versus asymmetric cross-sections. The present research addresses a number of classical derivations of methods with a focus on the work of Dwight Windenburg as published in "The Elastic Stability of Tee Stiffeners" and the expansion of his work to asymmetric sections by E. F Bruhn in Analysis and Design of Aerospace Vehicle Structures. Vagueness in the relevance of geometric symmetry of the bulb exists between Windenburg's plate theory approach, and the accepted industry standard applications defined in the methods of Bruhn. The results presented trace …

Development Of Automatic Cfd Grid Generation For The Design Of The Preliminary Wing Sweep Schedule For The Gulfstream Quiet Supersonic Jet, Ali Kazeneh

Master's Theses - Daytona Beach

The wing sweep schedule for the Gulfstream Quiet Supersonic Jet (wing and body) was investigated using CFD analysis methods. The use of automating the gridding procedure allowed for numerous cases to be investigated. The examination of the drag polar for different Mach cases indicated the optimum corresponding wing sweep position. The study results revealed that for the Mach 0.85 case, the wings should remain at the forward most pivoted position (Ʌ=25°). The Mach 1.1 case indicted that the wings should be in the fully swept back position (Ʌ=60°). The majority of the wing sweep transition occurs from Mach 0.85 to …

Implementation Of A Low Cost Micro Electro Mechanical Systems Inertial Navigation Solution, Charles Njenga

Master's Theses - Daytona Beach

The purpose of this study is to develop a low cost navigation solution for General Aviation (GA) aircraft and flight testing aircraft. This low cost solution uses a Global Positioning System (GPS) coupled with an Inertial Navigation Solution (INS) to provide a more accurate, stable navigation solution that can be acceptable for aircraft navigation. Lab VIEW was utilized to perform data acquisition and computation. LabVIEW was the backbone software to perform real time computation. MATLAB ® Simulink ® was used to plot graphs for final analysis of the code. A software Kalman Filter was utilized to provide signal stability and …

Wing Optimization Technique Based On Vortex Lattice Theory, Santiago Pinzon

Master's Theses - Daytona Beach

An integrated aerodynamic optimization technique based on vortex lattice theory is being proposed. The technique in this work will aim at optimizing the geometric parameters of a general wing with NACA 65-210 airfoil sections under a low speed aerodynamic regime. This will be completed by performing an aerodynamic analysis based on vortex lattice theory with the objective of satisfying a performance index function. This function will seek to optimize the high lift-to-drag ratio of the wing at cruise velocity, while maximizing theoretical cruise range and minimizing wing weight. The optimization method has been developed using MATLAB and the focus of …

The Influence Of Motivation And Investment On The Length Of Time Pilots Fly Into Degraded Weather, Bonnie M. Saxton

Master's Theses - Daytona Beach

Approximately 75% of weather-related accidents result in fatalities and are a primary safety concern in aviation. This study attempted to understand how financial motivation and time investment influence the length of time pilots fly into degraded weather. The sunk-cost effect claims that financially motivated pilots would continue longer when weather is encountered late in the flight. The results revealed that the financially motivated pilots continued longer than the non-financially motivated pilots when weather was encountered early in the flight. These results support the situation assessment hypothesis and cognitive anchoring. Specifically, how pilots assess the situation and utilize information obtained before …

Attitude Determination Using Imaging Lidar, Camille Decoust

Master's Theses - Daytona Beach

The purpose of this study is to determine the attitude of an out of control object using a new technology called lidar (Light Ranging and Detection). As the number of spacecraft continues to grow, it is paramount to introduce a new type of autonomous on-orbit satellite inspection and repair involving docking. Traditional space vision technology is based on video systems. This method is limited by the necessity of operating when the target is illuminated by the sunlight or using its own source of illumination. The use of laser imaging technology offers an elegant solution to these challenges. This approach allows …