Achieving best turbine blade cooling efficiency from a cylindrical cooling hole with reverse-vortex generator using numerical simulation

الملخص EN

This investigation bargains mathematical investigation of the impact of kidney vortex generation (KVG) on the film cooling execution of a round cooling opening which has measurement (d = 20 mm) on a level plate.

The collection between the stream cooling air and standard hot gases will result kidney vortex which will wipe out the film cooling adequacy.

Two kind of reverse vortex generator (RVG) with various statures (H = 0.5 d and 0.25 d) are intended to eliminate the kidney vortex and examine best film cooling adequacy, where every one of them is mounted to the level plate upstream of the cooling opening by changing its parallel positions (A = 0.0 d, 0.25 d, 0.5 d and 0.75 d) concerning the opening community line and for each kind has diverse distance regard to opening focus line.

The changing of blowing proportion (BP = 0.5-1.0) was considered in this investigation.

The simulation model was used to simulate the formation of film cooling using a shear stress transfer (SST) model by Workbench 15 software.

The outcomes have been introduced in terms of laterally averaged and maximum value of film cooling comparison diagrams, vorticy on x/d = 3.0 and film cooling distribution which clarified how the outcomes acquired.

The Cases 04 and 07 gave the best situations for RVG where case 04 gave wide covered for laterally average film cooling efficiency (n = 0.35), while case 07 gave the highest expansion distribution and the maximum value for film cooling efficiency (n = 0.66).

The best results are obtained when the blowing ratio (BP = 0.5) due to a lower velocity of cooling air which will made best interaction with the hot air (main stream)which will represent the hot gases in real case.