Generation of velocity fluctuations for inflow boundary condition of LES

In this study, inflow turbulence for LES was generated by the method of Hoshiya [Proc. JSCE 204 (1972) 121-128] based on Monte Carlo simulation considering power spectral density and cross-spectral density as targets. The generated inflow turbulence was modified to satisfy the continuity 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 prescribed spatial correlation and power spectral density and the level of velocity divergence was sufficiently reduced. To confirm the applicability of generated inflow turbulence, it was used as the inflow boundary condition for simulating decaying isotropic turbulence with the same conditions as the experiment by G. Comte-Bellot and S. Corrsin [J. Fluid Mech. 48 (1971) 273-337]. Decay of turbulence kinematic energy in the streamwise direction was reproduced well by LES using generated inflow turbulence.