Numerical investigation of laminar-plate transpiration cooling by the preconditioned density-based algorithm

The preconditioned density-based algorithm and two-domain approach were used to investigate the laminar-plate transpiration cooling process. In the porous zone, the momentum equations were formulated by the Darcy-Brinkman- Forchheimer model; and the local thermal equilibrium model (LTE) was adopted for the energy equation. At the porous/fluid interface, the stress-continuity interfacial condition was utilized. The effects of coolant injection rate, Reynolds number, pressure gradient of mainstream, and thermal conductivity ratio on the transpiration cooling performance were studied. Results indicate that the thickness of the coolant boundary layer on the protected surface has a significant effect on the transpiration cooling effect. Under the current conditions, the transpiration cooling performance would be enhanced with increasing coolant injection rate, but would be weakened with increasing Re. The adverse pressure gradient of mainstream would improve the transpiration cooling performance.