Large Eddy Simulation of Turbulent Square Duct Flow with Entropic Lattice Boltzmann Method

• Main Authors: Guo, M. J., 郭明誌
• Other Authors: Lin, C. A.
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/29031943579944220545

碩士 === 國立清華大學 === 動力機械工程學系 === 102 === In this study, the entropic Lattice Boltzmann method (ELBM) and the Large eddy simulation (LES) will be applied to simulate the 3D turbulent duct flow. Comparing of the LBGK, the ELBM can improve the numerical stability. Also, the LES with Smargorinsky subgrid-scale model is adopted to simulate the turbulent duct flow. When utilizing the D3Q19 model, the non-physical small counter-rotating vortex on the duct corner were observed when simulating turbulent duct flow. Due to this reason, we will follow Kang et al. [18] adopting D3Q27 model within ELBM framework to simulate turbulent duct flow. In the beginning, we simulate the laminar Poiseuille flow at frictional Reynolds number Re = 20 and compare with the analytic solution to validate that whether ELBM is capable to recover the Navier-Stokes equation. Second, we simulate Re = 300 for 3D turbulent Poiseuille flow in a square duct. Results show that our simulation can capture correctly the turbulent quantities compared with existing measurement and data of Direct Numerical Simulation (DNS). However, the present grid resolution is not adequate to fully capture the near wall turbulent structure.