Published online by Cambridge University Press: 04 July 2016
Film cooling performance expressed in the terms of film effectiveness, is divided into initial and final regions containing respectively, the potential core and transition lengths and, the main decay region. The theory of Kutateladze and Leont'ev, which is representative of present approaches, is presented and shown not to apply to the film initial region. To resolve the questions, what is the minimum acceptable value of effectiveness in a given situation, and, what proportion of the resulting maximum permissible cooled distance is initial region, the film cooling of a hypothetical turbojet engine to power a Mach 2-2 cruise supersonic air liner is examined. Experimental data from cooling devices representative of current European practice are used in the analysis to give realistic results.