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Full-Text Articles in Engineering

Liquid Jet Penetration And Breakup In A Free Supersonic Gas Jet, Hansen Jones Oct 2018

Liquid Jet Penetration And Breakup In A Free Supersonic Gas Jet, Hansen Jones

LSU Master's Theses

In the testing of today’s rocket engines, both on large scale vertical test stands and smaller subscale horizontal component testing stands, it is extremely important to be able to accurately quantify and mitigate the thermal and acoustic loads the engines will generate on test stand infrastructure. Due to the large number of parameters that must be considered for many cases, development of a multi-phase computational code is under way to properly analyze and design water spray cooling systems used at NASA’s Stennis Space Center (SSC) and across other NASA centers. As such, a small-scale experiment has been conducted ...


Computational Exploration Of Flash-Boiling Internal Flow And Near-Nozzle Spray, Sampath K. Rachakonda Jan 2018

Computational Exploration Of Flash-Boiling Internal Flow And Near-Nozzle Spray, Sampath K. Rachakonda

Doctoral Dissertations

Gasoline engines operating under the principle of direct injection are susceptible to flash-boiling due to superheated nature of the fuel and the sub-atmospheric in-cylinder pressures during injection. A review of the literature on flash-boiling sprays shows that a majority of the studies have focused on the far-field regions of the spray, with limited attention given to understanding the influences of the injector geometry and the near-nozzle regions of the spray. Modeling the internal nozzle flow and the primary atomization, on which the far-field spray depends, is a challenge. This thesis, therefore, is aimed at understanding the complex flow through a ...


The Development And Numerical Modelling Of A Representative Elemental Volume For Packed Sand, Ashraf Thabet Sep 2017

The Development And Numerical Modelling Of A Representative Elemental Volume For Packed Sand, Ashraf Thabet

Electronic Thesis and Dissertation Repository

The motivation of this thesis is the development of simple microscopic-scale model (representative elemental volume; REV) that can be used to conduct flow and heat transfer simulations from which closure coefficients can be established for the volume-averaged transport equations for porous media (packed bed). The thesis provides a brief introduction to the computational technique adopted for the geometric generation of the REV (YADE), followed by a parametric study undertaken to reveal the minimum number of particles inside the REV that are required to mimic the appropriate physics. Additional analysis was conducted with the goal of determining the influence of deviation ...


Project Oasis: Optimizing Aquaponic Systems To Improve Sustainability, Siddharth Nigam, Paige Balcom Jan 2016

Project Oasis: Optimizing Aquaponic Systems To Improve Sustainability, Siddharth Nigam, Paige Balcom

Honors Theses and Capstones

Started in Fall 2015, Project OASIS (Optimizing Aquaponic Systems to Improve Sustainability) is an interdisciplinary capstone project with the goal of designing a sustainable and affordable small-scale aquaponic system for use in developing nations to tackle the problems of malnutrition and food insecurity. Aquaponics is a symbiotic relationship between fish and vegetables growing together in a recirculating system. The project’s goals were to minimize energy consumption and construction costs while using universally available materials. The computational fluid dynamics (CFD) software OpenFOAM was used to create transient and steady-state models of fish tanks to visualize velocity profiles, streamlines, and particle ...


Eulerian Cfd Modeling Of Multiphase Internal Injector Flow And External Sprays, Eli T. Baldwin Jan 2016

Eulerian Cfd Modeling Of Multiphase Internal Injector Flow And External Sprays, Eli T. Baldwin

Doctoral Dissertations

The improvement of combustion systems which use sprays to atomize liquid fuel requires an understanding of that atomization process. Although the secondary break up mechanisms for the far-field of an atomizing spray have been thoroughly studied and well understood for some time, understanding the internal nozzle flow and primary atomization on which the far-field spray depends has proven to be more of a challenge. Flow through fuel injector nozzles can be highly complex and heavily influenced by factors such as turbulence, needle motion, nozzle imperfections, nozzle asymmetry, and phase change. All of this occurs within metallic injectors, making experimental characterization ...


Simulations And Measurements Of Fuel Film Using Refractive Index Matching Method, Fengkun Wang Jan 2014

Simulations And Measurements Of Fuel Film Using Refractive Index Matching Method, Fengkun Wang

Wayne State University Theses

ABSTRACT

SIMULATIONS AND MEASUREMENTS OF FUEL FILM USING REFRACTIVE INDEX MATCHING METHOD

by

FENGKUN WANG

APRIL 2014

Advisor: Dr. Ming-Chia Lai

Major: Mechanical Engineering

Degree: Master of Science

Direct Injection (DI) has been known for its improved performance and efficiency in gasoline spark-ignition engines. However, wall wetting is inevitable and the source of UHC and PM. In order to take advantage of the GDI technology, it is important to investigate spray wall interactions in detail.

Numerical and experimental studies are carried out for spray and wall impingements in an optical constant volume vessel. The fuel film was measured spatially and ...


Computational And Experimental Study On Vertical Axis Wind Turbine In Search For An Efficient Design, Mohammad M. Bashar Jan 2014

Computational And Experimental Study On Vertical Axis Wind Turbine In Search For An Efficient Design, Mohammad M. Bashar

Electronic Theses and Dissertations

Wind alone can fulfill most of the energy requirement of the world by its efficient conversion in to energy. Though Horizontal Axis Wind Turbine (HAWT) is more popular but needs high wind speed to generate energy. On the other hand Vertical Axis Wind Turbine (VAWT) needs low wind speed and can be installed anywhere which are some of the reasons for this research. The main objective of this research is to improve the design and performance of VAWT to make it more attractive, efficient, durable and sustainable. For a VAWT the blades perform the main role to extract energy from ...


Numerical Modelling Of Species Exchange In A 3d Porous Medium: Modelling Exchange Within The Human Lung, Chelsea E. Johnson Apr 2013

Numerical Modelling Of Species Exchange In A 3d Porous Medium: Modelling Exchange Within The Human Lung, Chelsea E. Johnson

Electronic Thesis and Dissertation Repository

The volume-averaged oxygen transport equation is closed using a volume-averaged form of Fick’s law of diffusion between the air and tissue to simulate species exchange within the lungs’ alveoli using a computational fluid dynamics (CFD) 3D conjugate domain model. Pore level simulations of a terminal alveolated duct are used to determine that the transport of inhaled oxygen from the cluster inlet to the alveolar walls is diffusion dominated. The resistance to oxygen diffusion into the tissue is found to be a function of the tidal volume and tissue transport properties, with a maximum respiration frequency at which the full ...


Parametric Study On A Novel Waste Heat Recovery System, Ghaleb Rustom Abdul Sater Dec 2012

Parametric Study On A Novel Waste Heat Recovery System, Ghaleb Rustom Abdul Sater

Electronic Thesis and Dissertation Repository

The present thesis is based on an industry-sponsor project involving a novel waste heat-to-electricity conversion system. This proprietary system utilizes thermal energy from a low temperature heat sources to produce torque that drives an electric generator to produce electricity. The system needs to be studied through scientific research to help with optimizing the product development, component design, and overall system performance. The main objectives of this study are to develop simulation tools (numerical model) that will allow to simulate the thermo-fluid processes in various system components and to use this numerical model to study the heat transfer and phase-change processes ...