Question: In film cooling the primary effect is believed to be due to the energy put into or taken out of the boundary layer, rather than the mass of fluid injected. If this is the case, it should be possible to approximate the effect of slot injection by simulating the slot with a strip heater in which the total heat rate is set equal to the product of the injection mass flow rate and the enthalpy of the injected fluid. Using the methods of the preceding two problems, carry out an investigation of the case represented by Eq.
η = 21.8(x/Mh)-0.8