Heat transfer analyses of film-cooled HP turbine vane considering effects of swirl and hot streak

Conjugate heat transfer (CHT) analyses were conducted on the film-cooled first stage vane of GE-E3 engine to reveal the influences of inlet swirl and hot streak (HS) on vane film cooling. Two cases with only HS and four cases considering with combined HS and swirl were studied, including the effects of HS/swirl to vane clocking positions (HS/swirl aligned to passage or vane) and swirl orientations (positive/negative). The results indicate that the variations of incidence angle combined with effects of radial transportation of the swirl vortex worsen the film coolant attachment, decrease the film cooling efficiency and increase the heat load onto vane surface. However, for film holes with radial angles toward the outer endwall, negative incidence near hub endwall is beneficial to the leading edge film coolant attachment. Therefore, a negative swirl aligned to the vane leads to lowering the temperature at the leading edge and the pressure side than the other three cases with combined swirl and HS. Heat transfer coefficient (HTC) on the suction surface (SS) is increased due to upwash and downwash of boundary layer fluids caused by swirl. The temperature on SS is therefore increased because the heat energy transferred from fluid to solid is increased.