Comparison on film cooling of different hole shapes at different blade heights on the suction surface of rotor blade
Simulations were performed to study the downstream film cooling performance of round holes,fan-shaped holes,and laid-back fan-shaped holes at different heights on the suction surface of a rotor blade.Film holes were located at streamwise location of 17.8％and at 10％,30％,50％,70％and 90％blade heights,respectively.The diameter of the round section of each shaped hole was 0.8 mm.Studies were conducted at rotational speed of 600 r/min,corresponding to rotational Reynolds numbers of 536 000.Five blowing ratios of 0.50,0.75,1.00,1.25 and 1.50 were involved.Results showed that under the effects of passage vortex and tip leakage flow,inward film deflection trend towards the mid-span on the suction surface differed at different blade heights,corresponding to different degrees of structural asymmetry of counter rotating vortex inside film trajectories at different blade heights.With the increase of blowing ratio,the height at which the highest film cooling effectiveness appeared gradually moved upward.The introduction of fan-shaped hole and laid-back fan-shaped hole weakened the normal momentum of the jet at the hole exit and improved film coverage and film cooling effectiveness.
film coolingrotor bladesuction surfaceblade heightsshapedholeblowing ratio
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万方数据
