Use of DNS Data for the Evaluation of Closure Models in Spanwise-Rotating Turbulent Channel Flow

A direct numerical simulation (DNS) of a spanwise-rotating turbulent channel flow was conducted for three rotation numbers: Roc = 0, 5.2 and 26, at a Reynolds number Rec = 8000. The data base obtained from these simulations was used to evaluate several commonly used Reynolds-Averaged Navier-Stokes (RANS-based) closure models for rotating turbulent channel flows. It was shown that the Reynolds stresses predicted by the Speziale-Gatski (SG) model were the most consistent with the DNS results. A correction to the Girimaji turbulence model was proposed to remove a discontinuity in the non-rotational case. The pressure-strain functions of the explicit algebraic Reynolds stress model (EARSM)-type SG and Girimaji models were examined and the modeled pressure-strain distributions of both turbulence models, especially near the suction wall, were demonstrated to become more accurate with increasing rotation number. The accuracy of the modeled pressure-strain was also shown to affect the accuracy of the corresponding modeled Reynolds stresses near the channel walls