Degree Type

Dissertation

Date of Award

2003

Degree Name

Doctor of Philosophy

Department

Mechanical Engineering

First Advisor

Richard H. Pletcher

Abstract

A compressible finite volume formulation for large eddy simulation (LES) of turbulent channel flows was extended to solve the turbulent flows in pipes and annular passages. A general finite volume scheme was developed based on conservation equations in Cartesian coordinates with non-Cartesian control volumes. A dual-time stepping approach with time derivative preconditioning was employed and time marching was done with an implicit lower-upper-symmetric-Gauss-Seidel (LU-SGS) scheme. The small scale motions were modeled by a dynamic subgrid-scale (SGS) model. The code was developed in a multiblock framework and parallelized using the message passing interface (MPI).;The finite volume LES formulation was validated by simulating the isothermal fully developed turbulent pipe and annular flows. The results were compared to experimental data and direct numerical simulation (DNS) results. The LES formulation was further validated by the simulation of turbulent pipe flows with low heat transfer and comparisons with passive scalar DNS results. Finally, buoyancy forces were added into the LES formulation to simulate mixed convection in a vertical pipe with constant high wall heat fluxes leading to significant property variations. Step-periodic boundary conditions were studied and implemented. The results were validated by comparing with experimental results. Heating effects and flow laminarization were studied.;Excellent agreement with DNS and experimental results were obtained for isothermal turbulent pipe and annular flows. The mean temperature profile for the turbulent pipe flow with low heat transfer matched very well with the DNS passive scalar results. Good matches to constant property correlations were also achieved for friction coefficients and Nusselt numbers.;For the mixed convection in a vertical pipe, good agreement with the experimental mean streamwise velocity and temperature profiles was obtained. High heating tended to suppress the turbulent intensities and attenuate the turbulent kinetic energy. The thinner viscous layer led to a larger Nusselt numbers which indicated a higher heat transfer rate. Laminarization phenomena were observed along with large overprediction of friction coefficients and underprediction of Nusselt numbers when comparing to fully turbulent property variation correlations.

DOI

https://doi.org/10.31274/rtd-180813-51

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu

Copyright Owner

Xiaofeng Xu

Language

en

Proquest ID

AAI3105120

File Format

application/pdf

File Size

153 pages

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