Aerospace Engineering Commons^™

Mitigation Of Moving Shocks In An Expanding Duct, Veraun Chipman

UNLV Theses, Dissertations, Professional Papers, and Capstones

Inviscid flow theory governs the bulk motion of a gas at some distance away from the walls (i.e. outside the boundary layer). That is to say, there are no viscous forces in the bulk flow, which is modeled using the Euler equations. The Euler equations are simply the Navier-Stokes equations with zero viscosity terms. An ideal inviscid fluid, when brought into contact with a surface or wall, would naturally slip right past it since the fluid has no viscosity. In real life, however, a thin boundary layer forms between the wall or surface and the bulk flow. Shock wave boundary …

Development Of An Exteroceptive Sensor Suite On Unmanned Surface Vessels For Real-Time Classification Of Navigational Markers, Christopher Lloyd Kennedy

Doctoral Dissertations and Master's Theses

This thesis presents the development of an exteroceptive sensor suite for real-time detection and classification of navigational markers on Unmanned Surface Vessels. Three sensors were used to complete this task: a 3D LIDAR and two visible light cameras. First, all LIDAR points were transformed from the sensor’s reference frame to the local frame using a Kalman filter to estimate instantaneous vehicle pose. Next, objects were chosen from the LIDAR data to be classified using either Multivariate Gaussian or Parzen Window Classifiers. Both produce 96% accuracy or better, however, multivariate Gaussian ran considerably faster than the Parzen and was simpler to …

Design And Dynamic Analysis Of A Variable-Sweep, Variable-Span Morphing Uav, Nirmit Prabhakar

Doctoral Dissertations and Master's Theses

Morphing wings have the potential to optimize UAV performance for a variety of flight conditions and maneuvers. The ability to vary both the wing sweep and span can enable maximum performance for a diverse range of flight regimes. For example, low-speed missions can be optimized using a wing with high aspect ratio and no wing sweep whereas high-speed missions are optimized with low aspect ratio wings and large wing sweep. Different static morphing wing configurations clearly result in varying aerodynamics and, as a result, varying dynamic modes. Another important consideration, however, is the transient dynamics that occur when transitioning between …

Vision-Aided Navigation For Gps-Denied Environments Using Landmark Feature Identification, Tennyson Samuel John

Doctoral Dissertations and Master's Theses

In recent years, unmanned autonomous vehicles have been used in diverse applications because of their multifaceted capabilities. In most cases, the navigation systems for these vehicles are dependent on Global Positioning System (GPS) technology. Many applications of interest, however, entail operations in environments in which GPS is intermittent or completely denied. These applications include operations in complex urban or indoor environments as well as missions in adversarial environments where GPS might be denied using jamming technology.

This thesis investigate the development of vision-aided navigation algorithms that utilize processed images from a monocular camera as an alternative to GPS. The vision-aided …

Cold Flow Performance Of A Ramjet Engine, Harrison G. Sykes

Master's Theses

The design process and construction of the initial modular ramjet attachment to the Cal Poly supersonic wind tunnel is presented. The design of a modular inlet, combustor, and nozzle are studied in depth with the intentions of testing in the modular ramjet. The efforts undertaken to characterize the Cal Poly supersonic wind tunnel and the individual component testing of this attachment are also discussed. The data gathered will be used as a base model for future expansion of the ramjet facility and eventual hot fire testing of the initial components. Modularity of the inlet, combustion chamber, and nozzle will allow …

Achieving Global Range In Future Subsonic And Supersonic Airplanes, Nihad E. Daidzic Ph.D., Sc.D.

International Journal of Aviation, Aeronautics, and Aerospace

No commercial airplane in service today is able to fly half great-circle distances over the globe and achieve the non-stop or the global range to any antipodal location on Earth. A subsonic jetliner has the optimum cruising speed at Mach numbers approaching the drag divergence Mach number while still preserving relatively high aerodynamic efficiency. Various fuel-flow laws were used to investigate the cruise performance of subsonic and supersonic aircraft. The effect of wind and aircraft weight and how it affects the optimal cruising airspeed was investigated. Of all different operational cruising techniques, the cruise-climb at high Mach numbers is the …

Potential Airborne Optical Contributions To The European Phased Adaptive Approach (Epaa) For Missile Defense, Garry Schnelzer, Sean Collins, Scott Hansen, Joe Kristl

Space Dynamics Laboratory Publications

Outline

• European Phased Adaptive Approach (EPAA)
• Airborne Optical Sensor’s Contribution and Coverage
• Notional Airborne Optical Sensor and Performance
• Recommendations

Space Hackathon: Magnitude.Io, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by Professor Bob Twiggs titled "Space Hackathon: Magnitude.io" from November 7, 2014.

The History Of Space Debris, Loretta Hall

Space Traffic Management Conference

This paper examines what space debris consists of and where it came from. In 1958, astronomer Clyde Tombaugh published the results of his research into the existence of natural debris near the Earth, concluding that no such debris existed. During the ensuing fifty-five years, man-made debris has been accumulating to the point that it threatens launches, active satellites, and the International Space Station. NASA reported that as of 2013, more than 21,000 pieces the size of a softball or larger were being tracked, as were about 500,000 pieces at least the size of a marble and “many millions” of pieces …

An Integrated Approach To Orbital Debris Research And Management, Marshall H. Kaplan

Space Traffic Management Conference

A viable space traffic management program faces a great barrier caused by the ever-increasing number and variety of orbiting objects ranging in size from a few microns to several meters. Although several international agreements to limit the growth rate of orbital debris are in place, the risk of damage and destruction to active satellites is continually rising. The urgency of this situation was highlighted by the 2007 Chinese ASAT test and the collision of Iridium and Cosmos satellites in 2009. Although many debris removal techniques have been posited none have been implemented. Unless a space debris reduction program is undertaken …

Where Is Space? And Why Does That Matter?, Bhavya Lal, Emily Nightingale

Space Traffic Management Conference

Despite decades of debate on the topic, there is no consensus on what, precisely, constitutes the boundary between airspace and outer space. The topic is mired in legal and political conundrums, and the easy solution to-date has been to not agree on a definition of space. Lack of a definition, some experts claim, has not limited space-based activities, and therefore is not a hurdle that must be overcome. There are increasing calls however in light of increasing (and expectations of increasing) space traffic, both orbital and sub-orbital. This paper summarizes the proposed delimitation of space, the current debate on whether …

Faa Letter In Response To White House Letter Regarding Faa Changes To Air Traffic Control Specialist Hiring Process, Tim Brady, Gregory Mcguirk

Publications

On July 18, 2014, you submitted a letter to President Obama regarding the Federal Aviation Administration's (FAA) recent changes to the Air Traffic Control Specialist (ATCS) hiring process. You expressed concern with the FAA's decision to implement a single all sources hiring strategy and, as a result, you feel that it has disadvantaged graduates who successfully completed the Air Traffic Collegiate Training Initiative (AT-CTI) program, such as xxx. You also expressed concern with the implementation of the Biographical Assessment. Your letter was forwarded by the White House to our agency to address your concerns.

Aerodynamic Optimization Of Box Wing – A Case Study, Adeel Khalid, Parth Kumar

International Journal of Aviation, Aeronautics, and Aerospace

The optimization of a possible medium range box wing commercial airliner is presented in three stages. Preliminary research is used to determine various parameters for a potential box wing model, and a baseline model is designed in Autodesk Inventor, based upon the cantilever Airbus A330-200, an aircraft of a similar role. The Computational Fluid Dynamics (CFD) software used in this project is Dassault Systèmes SolidWorks, which is validated through comparing the NACA 0009 airfoil lift and drag polars with published results. The first stage of optimization is performed on the airfoil shape, with 8 different designs being tested against the …

Ammonia Measurements And Emissions Estimates From A California, Usa Dairy Using Both Point And Remote Sensors, Kori Moore, Emyrei Young, Cassi Gurell, Michael Wojcik, Randall Martin, Gail Bingham, Richard Pfeiffer, John Prueger, Jerry Hatfield

Space Dynamics Laboratory Publications

Background

• Question: How much does a US open lot dairy contribute to local and regional PM loadings?
• • Primary PM: dust, combustion sources
  • Secondary PM: NH₃, NO_x, SO_x, VOCs
  • Climate, housing, manure management, and other confounding factors
• Emissions measurements are required to help answer this question
• Study Objective:
  • Characterize PM_2.5, PM₁₀, TSP, and gaseous NH₃concentrations, fluxes, and emissions from a commercial dairy using both point and remote sensing techniques
  • Results reported in:
    • Marchant et al. 2011. Estimation of dairy particulate matter emissions from a California dairy …Trans. ASABE …

Manufacturing Of Transparent Composites Using Vacuum Infusion Process, V. G.K. Menta, R. R. Vuppalapati, K. Chandrashekhara, Thomas P. Schuman

Chemistry Faculty Research & Creative Works

A novel optically transparent glass fiber reinforced polymer matrix composite has been developed by infusing a clear epoxy resin system of matching refractive index into a conventional E-glass fabric preform. Transparent composites are manufactured using a low cost, environmentally friendly vacuum infusion process. Physical and mechanical tests have been conducted. Transparent composites manufactured using the modified vacuum infusion process had a fiber volume fraction of 40%. Tensile strength and tensile modulus of these composites were 374.9 MPa and 31.74 GPa respectively. The results indicate that the transparent composites possess good physical and mechanical properties. These transparent composites form a good …

Study Of Energy Recovery And Power Generation From Alternative Energy Source, Abdulhakim Amer A. Agll, Yousif M. Hamad, Tarek A. Hamad, John W. Sheffield

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The energy requirement pattern of world is growing up and developing technology. The available sources, while exhausting and not friendly to the environment, are highly used. Looking at partial supply and different options of environment problems associated with usage, renewable energy sources are getting attention. MSW (Municipal solid waste) composition data had been collected from 1997 to 2009, in Benghazi Libya, to evaluate the waste enthalpy. An incinerator with capacity of 47,250 kg/h was confirmed to burn all the quantity of waste generated by the city through the next 15 years. Initial study was performed to investigate energy flow and …

Solid Waste As Renewable Source Of Energy: Current And Future Possibility In Libya, Tarek A. Hamad, Abdulhakim A. Agll, Yousif M. Hamad, John W. Sheffield

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Solid waste holds the greatest potential as biomass source in Libya. The rapid expansion of industry has led to increased urbanization and growing population. These factors have dramatically increased the amount of MSW (municipal solid waste) generated in Libya. However, issues related to environmentally sound MSW management - including waste decrease and clearance - have not been addressed sufficiently. This study presents an overview on solid waste that can be used as a source of bioenergy in Libya including MSW, ISW (industrial solid waste), and HSW (health care wastes) as biomass sources. The management of solid waste and valorization is …

A Cfd Investigation Of The Hydrodynamic Characteristics Of Fluid Flow Through An Impeller And Multi-Objective Design Optimization Of A Centrifugal Pump, Mohammed Khammat Sagban

Doctoral Dissertations and Master's Theses

In this thesis, the first part is conducting an investigation of the hydrodynamic characteristics (pressure and velocity) of fluid flow (water) through an impeller of a centrifugal pump. To illustrate a one-dimensional model is used to identify an impeller of a GDM 10 x 12 HD centrifugal pump using Vista CPD design and BladeGen tool. A three-dimensional model is then built with a commercial software package ANSYS Blade Modeler. The structured mesh of the impeller blade is obtained by using TurboGrid system. The volute of the centrifugal pump is built in ANSYS geometry, and an unstructured mesh is accomplished by …

A Continuous/Discontinuous Fe Method For The 3d Incompressible Flow Equations, Nikolaos Kyriazis

Doctoral Dissertations and Master's Theses

A projection scheme for the numerical solution of the incompressible Navier-Strokes equation is presented. Finite element discontinuous Galerkin (dG) discretization for the velocity in the momentum equations is employed. The incompressibility constraint is enforced by numerically solving the Poisson equation for pressure using a continuous Galerkin (cG) discretization. The main advantage of the method is that is does not require the velocity and pressure approximation spaces to satisfy the usual inf-sup condition, thus equal order finite element approximations for both velocity and pressure can be used. Furthermore, by using cG discretization for the Poisson equation, no auxiliary equations are needed …

Space Separatism: Degree Of Differentiation, Luke R. Stover, Alan A. Johnson

Faculty Publications

Space is so important that the DOD recognizes it as one of five domains in which US forces operate (the other four are land, sea, air, and information). In 2001 Secretary of Defense Donald Rumsfeld designated the Department of the Air Force (DAF) the “Executive Agent for Space for the DOD.” Given the national importance of space activities, the formation of a separate space force has been a topic of persistent discussion in academic and doctrinal circles ever since the United States first entered the space age. Proponents of a separate force argue that because space is an inherently unique …