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Articles 1 - 14 of 14
Full-Text Articles in Mechanical Engineering
Discrete Vortex Modeling Of Aerodynamic Flutter Of A Flat Plate With Damped Oscillations, Emma Chao
Discrete Vortex Modeling Of Aerodynamic Flutter Of A Flat Plate With Damped Oscillations, Emma Chao
UNLV Theses, Dissertations, Professional Papers, and Capstones
Aerodynamic flutter is the unstable oscillation of a body caused by the interaction of aerodynamic forces, structural elasticity, and inertial effects induced by vortex shedding. Current models of this phenomenon require finite element analysis and extensive computational power and processing time. The purpose of this study was to develop and validate a program that is faster and more efficient than existing approaches by using the discrete vortex method (DVM). By reducing the complexities of flutter to the shedding of vortices in an inviscid model of a two-dimensional flat plate with a torsional spring constant at its center, this phenomenon can …
Cfd Modeling Of Smoke Movement In An Atrium, Robin Wu
Cfd Modeling Of Smoke Movement In An Atrium, Robin Wu
UNLV Theses, Dissertations, Professional Papers, and Capstones
The purpose of this paper is to better understand the behavior of smoke movement in an atrium. Thus gives first responders and civilians in and out of building a better understanding
With the advancements of modern technology, computers and softwares make simulation models possible such as fire models to simulate fire and smoke movements. In this paper, a computational fluid dynamic (CFD) software Fire Dynamic Simulator (FDS) is used to conduct a series of atrium tests to investigate the effectiveness of smoke exhaust systems. FDS solves the Navier-Stokes equations appropriate for low speed flows (Ma < 0.3) with an emphasis on smoke, heat transport and CO2 concentrations from fires. The default turbulence model used in FDS simulation is the Large Eddy Simulation (LES), which is the solution of Navier-Stokes equations at low speed.
The compartment tested was 9 …
Improving The Efficiency Of Wind Farm Turbines Using External Airfoils, Shujaut Bader
Improving The Efficiency Of Wind Farm Turbines Using External Airfoils, Shujaut Bader
Masters Theses
Wind turbine efficiency typically focuses on the shape, orientation, or stiffness of the turbine blades. In this thesis, the focus is instead on using static fixed airfoils in proximity to the wind turbine to control the airflow coming out of the turbine. These control devices have three beneficial effects. (1) They gather air from “higher up” where the air is moving faster on average (and therefore has more kinetic energy in it). (2) They throw the used (and slowed down air) downwards. This means that any turbines in the wind farm behind the lead turbines do not get “stale” air. …
Steady State Simulation Of Pyrolysis Gases In An Inductively Coupled Plasma Facility, Nicholas C. Martin
Steady State Simulation Of Pyrolysis Gases In An Inductively Coupled Plasma Facility, Nicholas C. Martin
Graduate College Dissertations and Theses
An important step in the more efficient use of PICA (Phenolic Impregnated Carbon Ablator) as a Thermal Protection System (TPS) material for spacecraft is the understanding of its pyrolysis mechanics. The gases released during pyrolysis and their subsequent interaction with the reactive plasma environment is not yet well understood. The surface recession of PICA as it ablates during testing only makes the study and characterization of the chemical reactions more difficult. To this end, a probe has been designed for this study to simulate, in steady state, the pyrolysis gases within the UVM 30kW Inductively Coupled Plasma (ICP) Torch Facility. …
Optimizing The Telescope Assembly Alignment Simulator For Sofia, Zoe E. Sharp, Alex Quyenvo, Jennifer Briggs, Brian Eney
Optimizing The Telescope Assembly Alignment Simulator For Sofia, Zoe E. Sharp, Alex Quyenvo, Jennifer Briggs, Brian Eney
STAR Program Research Presentations
The Stratospheric Observatory for Infrared Astronomy (SOFIA) conducts research on a modified Boeing 747sp aircraft. By using a variety of infrared science instruments mounted on a 2.7 meter telescope, researchers can make discoveries about the galactic center, star formation, and various topics associated with a deeper understanding of our universe. To efficiently collect data through the SOFIA instruments, the instruments must be tested and prepared prior to being placed on the aircraft. Therefore, with the use of the Telescope Assembly Alignment Simulator (TAAS), researchers can design and construct improvements needed for these instruments to efficiently perform while in flight. The …
Assessment Of Critical Technologies For Gas Turbine Engines Using Numerical Tools, Vinicius Pessoa Mapelli, Guillermo Paniagua, Jorge Sousa
Assessment Of Critical Technologies For Gas Turbine Engines Using Numerical Tools, Vinicius Pessoa Mapelli, Guillermo Paniagua, Jorge Sousa
The Summer Undergraduate Research Fellowship (SURF) Symposium
In 2014 gas turbine engine has reached a market value of 82.5 billion dollars, of which 59.5% are related to aircraft propulsion. The continuous market expansion attracts more and more the interest of researchers and industries towards the development of accurate numerical techniques to model thermodynamically the entire engine. This practice allows a performance and optimization analysis before the actual experimental testing, reducing the time and required investment in the design of a new engine. In this paper, a recently developed open source numerical tool named “Toolbox for the Modeling and Analysis of Thermodynamic Systems” (T-MATS) is used to assess …
The Stability And Control Of The Single Track Vehicles, Shyngys Karimov, Martin Corless
The Stability And Control Of The Single Track Vehicles, Shyngys Karimov, Martin Corless
The Summer Undergraduate Research Fellowship (SURF) Symposium
Bicycles, motorcycles and scooters are all examples of the single track vehicles. The dynamics of the single track vehicle involve many degrees of freedom and various modes which govern its performance, making a complicated and interesting research topic. Motorcycle in motion can roll, yaw, and steer about the steering axis. It has three main modes which determine the motion and stability of it, they are weave, capsize, and wobble. The motorcycle performance is limited by the behavior of its modes, and if even one of the modes becomes unstable, the vehicle will roll over, and crash. The goal of this …
Development Of Cfd Models For The Purposes Of Exploring Free Surface Wave Phenomena, Leonard P. Stoehr
Development Of Cfd Models For The Purposes Of Exploring Free Surface Wave Phenomena, Leonard P. Stoehr
Masters Theses
With the push for finding alternative, green energy sources, the harnessing of energy from ocean and lake waves is becoming a more researched field. To fully understand the behavior of wave interactions and optimize designs to extract this energy, it is necessary to develop computer models that can accurately replicate this behavior. A case is presented in which previous work done using the wave tank found in the Western Michigan University fluids lab is examined. The case involves harnessing the energy generated by ocean waves through the usage of plates of different shapes resting horizontally on the water’s surface. The …
Development Of A Pyrotechnic Shock Simulation Apparatus For Spacecraft Applications, Joseph Binder, Matthew Mccarty, Chris Rasmussen
Development Of A Pyrotechnic Shock Simulation Apparatus For Spacecraft Applications, Joseph Binder, Matthew Mccarty, Chris Rasmussen
Aerospace Engineering
This report details the research, design, construction, and testing of a pyrotechnic shock simulation apparatus for spacecraft applications. The apparatus was developed to be used in the Space Environments Lab at California Polytechnic State University. It will be used for testing spacecraft components with dimensions up to 24”x12”x12” as well as CubeSats. Additionally, it may be used as an instructional or demonstrational tool in the Aerospace Department’s space environments course. The apparatus functions by way of mechanical impact of an approximately 20 lb stainless steel swinging hammer. Tests were performed to verify the simulator’s functionality. Suggestions for improvement and further …
Thermal Vacuum Integration For Cal Poly's Space Environments Laboratory, Chelsea Barackman, Steven Jackowski
Thermal Vacuum Integration For Cal Poly's Space Environments Laboratory, Chelsea Barackman, Steven Jackowski
Aerospace Engineering
The purpose of the senior project is to construct a thermal vacuum by utilizing a preexisting vacuum chamber in the Space Environments Lab, and a donated Advanced Thermal Sciences (ATS) chiller. While a thermal vacuum is already available on campus, building one for the Space Environments Lab would grant undergraduates access to the equipment, allowing a much better understanding of testing methods and procedures in use by the aerospace industry. This paper explains the design and analysis of the thermal vacuum (T-VAC) project as well as the operation and procedures required for the ATS chiller and fill/drain tank. The thermal …
Computational Investigations Of Characteristic Performance Improvements For Subkilogram Laser Micropropulsion, Richard Joel Thompson
Computational Investigations Of Characteristic Performance Improvements For Subkilogram Laser Micropropulsion, Richard Joel Thompson
Masters Theses
Experimental investigations have evaluated the feasibility of using laser-driven plasma microthrusters for small-thrust, high-specific-impulse space maneuvers, particularly for micro- and nanosatellite missions. Recent work made use of the Mach2 hydromagnetics code for the construction of an adequate computational model of the micro-thruster opera- tion. This thesis expounds on this previous work by extending the computational modeling capabilities, allowing for the determination of plasma plume properties and characteristic performance assessment of the microthruster; this allows for further computational investi- gation of the performance improvements achieved by new design considerations. Two par- ticular design changes are implemented and measured: (i) the simulation …
Use Of Time Varying Dynamics In Neural Network To Solve Multi-Target Classification, S. N. Balakrishnan, J. Rainwater
Use Of Time Varying Dynamics In Neural Network To Solve Multi-Target Classification, S. N. Balakrishnan, J. Rainwater
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Several types of solutions exist for multiple target tracking. These techniques are computation-intensive and in some cases very difficult to operate online. The authors report on a backpropagation neural network which has been successfully used to identify multiple moving targets using kinematic data (time, range, range-rate and azimuth angle) from sensors to train the network. Preliminary results from simulated scenarios show that neural networks are capable of learning target identification for three targets during the time period used during training and a time period shortly after. This effective classification period can be extended by the use of networks in coordination …
Decoupled Dynamics For Control And Estimation, S. N. Balakrishnan
Decoupled Dynamics For Control And Estimation, S. N. Balakrishnan
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Decoupling of the dynamical equations in polar coordinates is used to develop a control scheme for use in target-intercept problems with passive measurements. By defining a pseudo control variable in the radial coordinate, the radial dynamics is made independent of the transverse dynamics. After solving for the radial control, the transverse control is determined through solutions to a two-point boundary value problem. Numerical results from a six degree-of-freedom simulation which used the decoupled control indicate that it is better than the completely Cartesian coordinate control for most of the cases considered. Decoupled control, though, is obtained iteratively through a two-point …
Development Of Helicopter Flight Path Models, Alfred Fermelia, Donald A. Gyorog, V. J. Flanigan
Development Of Helicopter Flight Path Models, Alfred Fermelia, Donald A. Gyorog, V. J. Flanigan
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The objective of this paper is to present general techniques for simulating helicopter flight trajectory response. During flight the pilot manipulates the controls either to trim the helicopter for steady flight by balancing the external forces and moments or to produce a desired maneuver by controlling the unbalance of these forces and moments. Discussions of the physical phenomena involved with the aerodynamics of the rotors and fuselage are given in [1] through [3]. The simulated control function will be composed forward-aft cyclic, lateral cyclic, pedal, and collective. This control will be represented by the vector