Award Date

May 2023

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Mechanical Engineering

First Committee Member

Yi-Tung Chen

Second Committee Member

Jeremy Cho

Third Committee Member

Mohamed Trabia

Fourth Committee Member

Hui Zhao

Fifth Committee Member

Stephen Lepp

Number of Pages

116

Abstract

The scope of this thesis is to numerically investigate condensation that occurs in transonic and supersonic flows. Condensation shocks are a phenomenon that occurs within converging-diverging nozzles. There are many applications forconverging-diverging nozzles, such as thermovapour compressors (TVC), which are largely used for desalination. As water resources become more precious within the western United States there is a need to develop cost effective solutions for cleaning water. Steam generator power stations are another application where enhanced simulations and accuracy of design could improve efficiency and save on carbon emissions. Traditionally, numerical designs of transonic flows have been conducted with either an ideal gas equation of state (EoS), which ignores condensation, or a homogeneous equilibrium approach, which assumes the fluid to be in thermo-dynamic equilibrium. The classical theory of nucleation was developed through the kinetic theory of gases to explain the process of condensation in supersonic flows, which occurs in a metastable state. The theory has recently been implemented in commercial codes and enjoys some success, particularly in low pressure flows. Improvement of the theory of classical nucleation in both high pressure and low pressure flows can help to improve the design of a multitude of systems. Through a self developed code that simulates one-dimensional transonic vapour flow through a converging-diverging nozzle, a new isothermal correction was developed. This new isothermal correction brings greater accuracy to simulations of homogeneously condensing high pressure flows and proved to be more accurate than the present theory in some lower pressure simulations.

Keywords

nozzle; phase change; transonic flow

Disciplines

Aerodynamics and Fluid Mechanics

Degree Grantor

University of Nevada, Las Vegas

Language

English

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/


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