Influence of the computational domain on DNS of turbulent heat transfer up to Re_τ = 2000 for Pr = 0.71

摘要

We present a new set of direct numerical simulation data of a passive thermal flow in a turbulent plane Poiseuille flow with constant Prandtl numberPr=0.71, and mixed boundary conditions. Simulations were performed atReτ=500,1000, and 2000 for several computational domains in the range oflx=2πhto8πhandlz=πhto3πh. As a first key result we found that a length oflx=2πhand a width oflz=πis enough to accurately obtain the one-point statistics and the budgets of the thermal kinetic energy, its dissipation and the thermal fluxes. None of them collapse exactly in wall units. On the other hand, the value of the thermal Kármán constant grows very slightly with the Reynolds number with a value ofκth=0.44forReτ=2000. The statistics of all simulations can be downloaded from the web page of ourhttp://personales.upv.es/serhocal/group.