A Comparison of Various Turbulence Models for Analysis of Fluid Microjet Injection into the Boundary Layer over a Flat Surface

The present work studied various models for predicting turbulence in the problem of injecting a fluid microjet into the boundary layer of a turbulent flow. For this purpose, the one-equation Spalart-Allmaras (SA), two-equation k-$\epsilon$ and k-$\omega$, multi-equation transition k-kL-$\omega$, transition shear stress transport (SST), and Reynolds stress models were used for solving the steady flow. Moreover, the transition SST, scale-adaptive simulation (SAS), and detached eddy simulation (DES) models were used for the transient flow. A comparison of the results indicated that the steady solution methods performed sufficiently well for this problem. Furthermore, it was found that the four-equation transition SST model was the most accurate method for the prediction of turbulence in this problem. This model predicted the velocity along the x-axis in near- and far-jet locations with about 1% and 5% errors, respectively. It also outperformed the other methods in predicting Reynolds stresses, especially at the center (with an about 5% error).