基于LBM-LES的三维串列多圆柱绕流尾涡结构研究

In order to study the wake structure of three-dimensional tandem multi-cylinder flow at differentI/D (L is the spacing between the cylinders and D is the diameter of the cylinder) , based on the latticeBoltmann method (LBM) , the large eddy simulation ( LES)method was used to calculate the wake flowfield of three-dimensional single cylinder and three-dimensional series multi-cylinder under different L/Dconditions. The results show that LBM-L.ES method can well simulate the wake structure of three-dimen-sional single cylinder and multi-cylinder in series. The wake change of single cylinder with high Reynoldsnumber is unstable.There is a critical spacing ratio L/D=4. When the spacing ratio between cylinders issmaller than the critical spacing ratio , there is no vortex shedding between the cylinders. When the criticalspacing ratio l/D is 4 , the vortex shedding phenomenon is obvious , and the vortex falling off the front cyl-inder affects the rear cylinder , which will have a certain impact on the vibration amplitude of the lift and drag coefficients of the rear cylinder. When the ratio of cylinder spacing is smaller than the critical spac-ing ratio , the time average resistance coefficient curve of the upstream and the downstream of the flow a-round multiple cylinders in series will tum at the critical spacing ratio.When the boundary spacing ratio is4 , adding a cylinder in front of the downstream cylinder will affect the time average resistance coefficient ofthe downstream cylinder and the midstream cylinder. But when the cylinder spacing ratio is greater thanthe critical spacing ratio of 4 , adding a cylinder in front of the downstream cylinder does not affect the timeaverage resistance coefficient of the downstream cylinder or the middle cylinder. The research results havecertain theoretical reference value for practical engineering.