Grid-point requirements for large eddy simulation: Chapman's estimates revisited

Resolution requirements for large eddy simulation (LES), estimated by Chapman [AIAA J. 17, 1293 (1979)], are modified using accurate formulae for high Reynolds number boundary layer flow. The new estimates indicate that the number of grid points (N) required for wall-modeled LES is proportional to Re-Lx but a wall-resolving LES requires N similar to Re-Lx(13)/(7), where L-x is the flat-plate length in the streamwise direction. On the other hand, direct numerical simulation, resolving the Kolmogorov length scale, requires N similar to Re-Lx(37/14). (C) 2012 American Institute of Physics. [doi:10.1063/1.3676783]