Date of Award
Doctor of Philosophy
Richard H. Pletcher
A compressible finite volume formulation for large eddy simulation has been extended to solve a variety of flows by using dynamic subgrid-scale stress model and dynamic Prandtl number model. The basic features of this finite volume formulation include a dual time stepping approach with time derivative preconditioning, an implicit low-upper symmetric Gauss-Seidel scheme, multiblock framework, and parallelization using message passing interface;Implementation of the dynamic model is validated by simulating a plane channel flow with constant heat flux. Good agreement between the present results and benchmark results in the literature is observed. Rotating channel flows with heat transfer are studied by adding a rotation source term. The effects of system rotation on the turbulent heat transfer are investigated. Finally, a rib-roughened channel flow is simulated both with and without heat transfer;The large eddy formulation with a dynamic model generally provided excellent agreement with direct numerical simulation results and experimental results for turbulent flows with heat transfer. For the constant heat flux channel flows, high heating tends to reduce the velocity fluctuations, while high cooling tends to enhance the fluctuations. The mean and fluctuation velocity profiles approach the incompressible results when normalized by local properties, as opposed to wall values. Spanwise system rotation is found to suppress turbulent velocity fluctuations and shear stresses near the stable side of the channel, but enhance the fluctuations and shear stresses near the unstable side. Turbulent temperature fluctuations and turbulent heat flux decreased near the stable side of the channel, but increased near the unstable side of the channel. In the case of the rib-roughened channel flow, a small recirculation zone before the rib and a larger recirculation zone after the rib are observed. Increased turbulent fluctuations and heat transfer are found around the rib.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Meng, Ning, "Large eddy simulation of turbulent flows with property variations, rotation and complex geometry " (2000). Retrospective Theses and Dissertations. 12706.