DOI: 10.1615/TSFP6
COMPARISON OF TURBULENT BOUNDARY LAYERS AND CHANNELS FROM DIRECT NUMERICAL SIMULATION
ABSTRAKT
A new simulation of the zero-pressure-gradient turbulent boundary layer is discussed, in the range Reθ = 620 − 2140. It is first shown that the initial several hundred momentum thicknesses have to be discarded due to contamination from the synthetic turbulent inflow, and this is traced to the long lifetimes of the largest eddies.
Beyond the inflow region, the results agree well with previous simulations and with experiments, and are compared to those of turbulent channels in the same range of Reynolds numbers. It is found that the transverse velocities and the pressure fluctuations are stronger in boundary layers. The reason is traced to the extra production in the wake region, and, ultimately, to the irrotational intermittency in that part of the flow.