THE EFFECT OF INJECTION HOLE LENGTH ON FILM-COOLING WITH BULK FLOW PULSATIONS

Bulk how pulsations in the form of sinusoidal variations of velocity a nd static pressure at injectant Strouhal numbers from 0.1-10.1 are inv estigated as they affect film cooling from a single row of simple angl e holes. Similar flow variations are produced by potential flow intera ctions and passing shock waves near turbine surfaces in gas turbine en gines. Time-averaged temperature distributions, phase-averaged tempera ture distributions, adiabatic film cooling effectiveness values, and i so-energetic Stanton numbers show that important alterations to film c ooling protection occur at different ranges of frequencies and coolant Strouhal numbers as non-dimensional injection hole length is changed. (C) 1998 Elsevier Science Ltd. All rights reserved.