A Sensitized-RANS, Reynolds-Stress Modeling Study of Flow and Thermal Fields affected by Streamline Curvature

The present study focuses on performing scale-resolving simulations of turbulent flow configurations exhibiting a wide range of differently structured phenomena, including flows influenced by strong streamline curvature, which is characteristic of thermal mixing of flow-crossing streams, and jet impingement on heated walls. These scenarios are commonly encountered in thermotechnical piping systems and internal combustion engines. The anisotropic turbulence residing in the unresolved motion is described by a RANS-based (Reynolds-averaged Navier-Stokes) eddy-resolving closure that accounts for the dynamics of the entire sub-scale stress tensor. The eddy-resolving capability of the model is achieved by introducing an additional production term in the length-scale determining transport equation, whose functional dependence on the second derivative of the underlying velocity field is motivated by the scale-adaptive simulation (SAS) strategy of Menter and Egorov (2010, FTaC 85), Jakirlic and Maduta (2015, IJHFF 51). The flow configurations considered take into account differently structured jets impinging on heated walls, as well as thermal mixing of flow-crossing streams. Comparative evaluation of the results along with available reference experiments and DNS (Direct Numerical Simulation), illustrates the correctly predicted instantaneous character of the flow as well as its time-averaged pattern.