Discharge coefficient of film cooling holes with rounded entires or exits

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The use of the '"additive loss" approach was found to lead to satisfactory predictions of discharge coefficients over the range of rounding and crossflows considered. the prediction procedure was applied to generate cd data in situations not originally included in the correlations, i.e. in the presence of two simultaneous crossflows, at higher crossflow mach numbers and at higher operating mainstream temperatures. good agreement was obtained between measured and predicted cd data in the presence of two crossflows. no previous cd data at higher crossflow mach numbers were available for comparison with the present predictions. the predictions showed that cd was independent of mainstrean temperature confirming pre vious experimental results. comparisons with these results showed good agreement for the 30° inclined holes, but differences of up to 30% occured for the normal holes. a computational fluid dynamics program called phobnics, was used to provide two and three dimensional solutions of a jet issuing prependicularly into a crossflow and that of a crossflow at a 90° nole entry. solutions were obtained with sharp-odged and with rounded hole entry and exit, the effect of the crosaflowu on the flow inside the hole was examined for both flow aituations considered.