Numerical simulation of heat transfer physics of film cooling under rotating conditions

Large eddy simulation was used to investigate the effect of rotation on film cooling over flat plate with single hole.The Reynolds number at the jet exit was 2600,and the blowing ratio was 0.5.The flow and heat transfer without rotation and with rotating number of 0.02 were calculated,and the heat transfer mechanics under rotating condition was analyzed through the evolvement of turbulence structure.It was found that hairpin structure determined the heat transfer of film cooling,and the shape and trajectory of hairpin structure was mainly affected by Coriolis force under rotating condition.The film was driven towards high radius side by spanwise Coriolis force,resulting in less mixing between main flow and jet and maintaining low temperature of the film.The Coriolis force normal to the wall reinforced the film attachment and reduced the strength of counter rotating vortex pair,leading to less entrainment of mainflow and better coverage of film.