Performance of film cooling with a negative longitudinal pressure gradient

Efficiency of film cooling in a curvilinear channel between guide blades

“…In all these studies the efficiency of film cooling was measured under so-called ideal conditions, and most authors singled out three zones: an initial zone, a transition zone, and a main zone, with the efficiency being a different function of m, | l~e s, and x/s in each. Only a few studies [5][6][7][8][9][10] have dealt with the effect of a longitudinal pressure gradient on the cooling efficiency, as such a gradient may cause both streams in actual turbines to mix during film cooling.…”

“…The tests were performed with either forward or reverse heal flow, with specially electrically preheated air injection into the cold mainstream. Such an injection was effected through a tangential orifice For this reason, the results from [10] were not used for evaluating our test data.…”