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Full-Text Articles in Mechanical Engineering
An Optimization Procedure To Design Nozzle Contours For Hypersonic Wind Tunnels, Omar Antonio Dominguez
An Optimization Procedure To Design Nozzle Contours For Hypersonic Wind Tunnels, Omar Antonio Dominguez
Open Access Theses & Dissertations
Supersonic wind tunnels allow scientists and researchers to evaluate and analyze the behaviors of objects under real-life conditions when subjected to supersonic speeds. One of the main complexities when building a wind tunnel is the design of the convergent-divergent nozzle that is used to produce high-speed and high-quality flows. To achieve supersonic speeds, this nozzle adopts a specialized approach that incorporates the complexities of flow compressibility. The compressible effect is accurately evaluated using isentropic relations, allowing for precise determination of stagnation pressure and temperature, and static pressure and temperature relevant to the desired Mach number. Isentropic equations used to define …
Computational Analysis Of Water Braking Phenomena For High-Speed Sled And Its Machine Learning Framework, Jose A. Terrazas
Computational Analysis Of Water Braking Phenomena For High-Speed Sled And Its Machine Learning Framework, Jose A. Terrazas
Open Access Theses & Dissertations
Specializing in high-speed testing, Holloman High-Speed Test Track (HHSTT) uses a process called "water braking" as a method to bring vehicles at the test track to a stop. This method takes advantage of the higher density of water, compared to air, to increase braking capability through momentum exchange. By studying water braking using Computational Fluid Dynamics (CFD), forces acting on track vehicles can be approximated and prepared for prior to the actual test. In this study, focus will be made on the brake component of the track sled that is responsible for interacting with the water for braking. By discretizing …
The Effect Of K2co3 Concentration In Kerosene Emulsions On Spray Droplet Sizes For A Magnetohydrodynamic Power Generator, Alejandra Castellano
The Effect Of K2co3 Concentration In Kerosene Emulsions On Spray Droplet Sizes For A Magnetohydrodynamic Power Generator, Alejandra Castellano
Open Access Theses & Dissertations
Potassium carbonate (K2CO3) is an effective seeding material to introduce potassium vapor in oxy-fuel combustion to create a conductive plasma. Injecting potassium carbonate before combustion promotes particle volatilization and improves the generation of potassium vapor. This can be achieved by emulsifying a potassium carbonate solution with kerosene. Several studies have investigated creating stable emulsions with kerosene with water by using differing surfactants. However, the effects of using varying concentrations of K2CO3 dissolved in deionized water have not been fully explored. Based on methods of creating successful emulsions, the development of a successful mixture comprised of kerosene and K2CO3 solution is …
Machine Learning Analysis To Characterize Phase Variations In Laser Propagation Through Deep Turbulence, Luis Fernando Rodriguez Sanchez
Machine Learning Analysis To Characterize Phase Variations In Laser Propagation Through Deep Turbulence, Luis Fernando Rodriguez Sanchez
Open Access Theses & Dissertations
The present Dissertation is focused on the analysis of the atmospheric conditions of a turbulent environmental system and its effects on the diffraction of a laser beam that moves through it. The study is based on the optical communication of two labs placed at the summit of two mountains located in Maui, Hawaii. The emitter system is located at the Mauna Loa mountain and the receiver at the Haleakala. The distance between both mountains is 150 km. The emitter system is at a height of 3.1 km and the receiver at 3.4 km. The maritime environment at the location experiences …
Implementing Large Eddy Simulation To Numerical Simulation Of Optical Wave Propagation, Diego Alberto Lozano Jimenez
Implementing Large Eddy Simulation To Numerical Simulation Of Optical Wave Propagation, Diego Alberto Lozano Jimenez
Open Access Theses & Dissertations
In this study, we want to simulate long-range laser propagation in atmospheric turbulence. The numerical simulations are carried out to study the impact of strong atmospheric turbulence in spatial, temporal, and related spectral domains. The first section of this study will be concerned with modeling this numerical simulation in Kolmogorov and non-Kolmogorov spectrum. To validate our numerical simulation, we will compare the statistical parameter to theoretical approximation in both Kolmogorov and non-Kolmogorov spectrums. Once the code is validated, we want to integrate Large Eddy Simulation (LES) turbulence modeling. LES simulations allowa us to study strong fluid turbulence and can predict …
Data-Driven Predictive Framework For Modeling Complex Multi-Physics Engineering Applications, Arturo Schiaffino Bustamante
Data-Driven Predictive Framework For Modeling Complex Multi-Physics Engineering Applications, Arturo Schiaffino Bustamante
Open Access Theses & Dissertations
Computational models are often encountered in multiple engineering application, such as structural design, material science, heat transfer and fluid dynamics. These simulations offer the engineers the capability of understanding complex physical situations before putting them to practice, either through experimentation or prototyping. The current advances in computational sciences, hardware architecture, software development and big data technology, have allowed the construction of sturdy predicting frameworks for analyzing a wide array of natural phenomena across different disciplines, either through the implementation of statistical methods, such as big data, and uncertainty quantification, or through high performance computing of a numerical model. The objective …
Design And Experimental Investigation Of An Oxy-Fuel Combustion System For Magnetohydrodynamic Power Extraction, Manuel Johannes Hernandez
Design And Experimental Investigation Of An Oxy-Fuel Combustion System For Magnetohydrodynamic Power Extraction, Manuel Johannes Hernandez
Open Access Theses & Dissertations
A general consensus in the scientific and research community is the need to restrict carbon emissions in energy systems. Therefore, extensive research efforts are underway to develop the next generation of energy systems. In the field of power generation, researchers are actively investigating novel methods to produce electricity in a cleaner, efficient form. Recently, Oxy-Combustion for magnetohydrodynamic power extraction has generated significant interest, since the idea was proposed as a method for clean power generation in coal and natural gas power plants. Oxy-combustion technologies have been proposed to provide high enthalpy, electrically conductive flows for direct conversion of electricity. Direct …
Analysis Of Road Vehicle Aerodynamics With Computational Fluid Dynamics, Christian Armando Mata
Analysis Of Road Vehicle Aerodynamics With Computational Fluid Dynamics, Christian Armando Mata
Open Access Theses & Dissertations
A road vehicles aerodynamics can be one of the most influential aspects of its performance. With the increased importance on fuel efficiency in recent years, new road vehicles are being developed smaller in size, with smaller displacement engines, as well as with improved aerodynamics. The aerodynamics of a vehicle can have a significant effect on its fuel efficiency, as well as other important aspects of the vehicles performance such as the top speed, acceleration, and handling. A study focusing on analyzing aerodynamic effects due to vehicle geometries such as wheels covered by the vehicles body in comparison to open wheels …
Simulation Of Infiltrating Rate Driven By Surface Tension-Viscosity Of Liquid Elements From The Titanium Group Into A Packed Bed, Arturo Medina
Simulation Of Infiltrating Rate Driven By Surface Tension-Viscosity Of Liquid Elements From The Titanium Group Into A Packed Bed, Arturo Medina
Open Access Theses & Dissertations
The simulation of infusion of molten reactive metals (e.g., yttrium) into a porous, carbide packed bed to create carbide and boride composites was studied at ultrahigh temperatures (>1700°C). The infusion was investigated through a computational fluid dynamic (CFD) system of capillary pores and compared to a predicted analytical calculation formulated by Selmak and Rhines. Simulations of two-phase flow penetration of yttrium into a packed bed of B4C were investigated and compared with titanium, zirconium, hafnium, and samarium liquids. The non-reactive, liquid metal infusion was primarily driven by the surface tension and viscosity. The liquid metal depth and rate of …