Stochastic generation of velocity fluctuation for turbulent inflow and initial condition

Direct or large eddy simulation of a turbulent °ow ¯eld is strongly
in°uenced by its initial or in°ow boundary condition. This paper aims to present a
new stochastic approach to generate an arti¯cial turbulent velocity ¯eld for initial
or in°ow boundary condition based on digital ¯ltering. The generated velocity ¯eld
reproduces locally desired Reynolds-stress components and integral length scales
including cross-integral length scales. The method appears to be simple, °exible and
more accurate in comparison with previously developed methods. The accuracy and
performance of the method is demonstrated by Direct Numerical Simulation(DNS)
of a homogeneous turbulent shear °ow. To assess the accuracy and performance of
the method, simulation results are compared with a reference simulation.