Experimental results of the corrective film heat transfer coefficient at the hot gas-side of the wall for full coverage discrete hole film cooling are presented for a range of practical geometries. The results are reported for various hot gas mainstream-to-coolant temperature (density) ratios, in the realistic range of 1.0–3.2. For combustor wall and turbine blades film cooling applications, the corrective film heat transfer coefficient was influenced significantly by the design parameters. It decreased with an increase in the number of holes per unit wall surface area, over the range of 4306–26910 m−2 and with an increase in the hole size, in the range of 1.0–2.2 mm, due to the improvement in film cooling. This was supported by the overall cooling effectiveness results, as reported previously (Bazdidi-Tehrani and Andrews 1994). A comparison between the two approaches for the prediction of the convective film heat transfer coefficient was made. It showed that the higher wall overall heat transfer, obtained using the present measurements of the wall overall heat transfer coefficient, resulted in a considerably higher film heat transfer coefficient than that predicted using the summation of the hole approach surface correlation of Sparrow (1982) and the internal hole correlation of Mills (1962). The variation of the mainstream-to-coolant temperature ratio did not establish consistent trends for various configurations and its effect on the film cooling performance was shown to be small.

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