A digital filter based generation of inflow data for spatially developing direct numerical or large eddy simulations

In contrast to time-evolving turbulence, direct numerical or large eddy simulations of spatially inhomogeneous flows require turbulent inflow boundary conditions, that make the results strongly influenced by the velocity profiles to be prescribed. This paper aims to present a new approach for generating artificial velocity data which reproduces first and second order one point statistics as well as a locally given autocorrelation function. The method appears to be simple, flexible and more accurate than most of the existing methods. This is demonstrated in two cases. First, direct numerical simulations of planar turbulent jets in the Reynolds number range from 1000 to 6000 are performed. Because of the importance of the primary breakup mechanism of a liquid jet in which inflow influences are evident, the new procedure is secondly used, to study atomization in dependence of the flow inside the nozzle by means of a Volume of Fluid scheme.