GENERATION OF VELOCITY FLUCTUATIONS FOR INFLOW BOUNDARY-CONDITION OF LES

In this study, inflow turbulence for LES was generated by the method o f Hoshiya [Proc. JSCE 204 (1972) 121-128] based on Monte Carlo simulat ion considering power spectral density and cross-spectral density as t argets. The generated inflow turbulence was modified to satisfy the co ntinuity equation by divergence-free operation based on the method of Shirani et al. [Report TF-15, 1981, Mechanical Engneering Department, Stanford University]. As a result, inflow turbulence satisfied the pre scribed spatial correlation and power spectral density and the level o f velocity divergence was sufficiently reduced. To confirm the applica bility of generated inflow turbulence, it was used as the inflow bound ary condition for simulating decaying isotropic turbulence with the sa me conditions as the experiment by G. Comte-Bellot and S. Corrsin [J. Fluid Mech. 48 (1971) 273-337]. Decay of turbulence kinematic energy i n the streamwise direction was reproduced well by LES using generated inflow turbulence.