Calculations of the drag coefficient of circular, square and rectangular cylinders using the lattice Boltzmann method with variable lattice speed of sound

Abstract

In this work, we studied the calculation of the drag coefficient using the lattice Boltzmann method with variable lattice speed of sound. The modified method of calculation the drag coefficient that includes the kinematic viscosity dependence was proposed. Calculations were based on the variable lattice speed of sound values that depend on the kinematic viscosity and the computational grid resolution. Shown the influence of the Reynolds number on the flow pattern and on the drag coefficient. The relation between the lattice Mach number and the computational grid resolution have been shown. The influence of the lattice Mach number on the accuracy of the numerical results was studied in detail. Shown that proposed method is more efficient because the researcher can set the kinematic viscosity of the fluid and the computational grid resolution at the same time. Therefore there is an opportunity to control the accuracy of the numerical results and the modeling time.