Numerical investigation of twin-jet impingement with hybrid-type turbulence modeling

•LES & SST–SAS hybrid model were applied for the first time for impinging twin-jets.•The numerical investigation was carried out for different spacing and Reynolds number.•Both approaches were not able to produce accurate results for heat transfer.•SST–SAS produced good results in terms of pressure distribution & velocity.

A Computational Fluid Dynamics (CFD) study of a twin-jet impingement is performed using the Reynolds-Averaged Navier–Stokes (RANS) approach with a dynamic Smagorinsky Large Eddy Simulation (LES). The use of a hybrid RANS–LES (i.e., part of the turbulence is modeled and part of the turbulence is resolved) method potentially offers a compromise between the computational efficiency and the accuracy comparable with that of a pure dynamic LES. In the current study, the SST–SAS (Shear-Stress transport with Scale-Adapted Simulation) k–ω model having hybrid RANS–LES characteristics is utilized for turbulence modeling. Effects of nozzle-to-plate (H/D) and nozzle-to-nozzle (L/D) distances on the pressure distribution and the heat transfer are investigated for 3 × 104 < Re < 5 × 104. Numerical results of SST–SAS and dynamic LES methods are validated against available experimental data. The flow expands radially as H/D increases. Results show that the SST–SAS model can produce fairly accurate results, especially with a lower H/D at which the sub-atmospheric region appears. In addition, the SST–SAS model is capable of predicting the peak values of local Nusselt number at correct locations.