Development of a parallelized computational fluid dynamics solver for turbulent bubbly flows in complex geometries and its applications to various flow problems

This thesis focuses on developing a computationally-efficient flow solver in the area of computational fluid dynamics. The contribution pertains to the mathematical and numerical development of solution techniques for simulating multiphase turbulent bubbly flows on parallel computers. In accomplishing this objective the following advances are obtained: 1) Development of a mathematical formulation to perform large-eddy simulation of the two-phase two-way coupled bubbly flows at low gas holdups in a purely Eulerian framework. 2) Development of a moving least squares reconstruction method for use in the sharp interface immersed boundary method for simulating flows in complex and moving geometries. In addition, an enhancement specific to incompressible flows is formulated and implemented that improves the solution accuracy and rate of convergence. The developed solver is used to make the following contributions to applied fluid mechanics: 1) Investigating the physics of a bubble column by efficiently characterizing the multiphase turbulent flow in terms of first and second-order statistics, turbulence kinetic energy and power spectral density. 2) Demonstrating how the discharge rate can be computed for a geometrically-complex axial pump via LES using the immersed boundary method. 3) Identifying the turbulence dynamics in the Taylor-Couette flow between concentric rotating cylinders. The research accomplishes this by using the developed flow solver to conduct several large-eddy simulations of Taylor-Couette flows, with the aim of characterizing the turbulent flow physics.Applied Science, Faculty ofEngineering, School of (Okanagan)Graduat