As demonstrated in Table 2, calcula

As demonstrated in Table 2, calculation of the various heat flows requires knowledge of the temperatures of various regions of the double-wall geometry which are largely unknown, with the exceptions of the mainstream gas and coolant inlet temperatures, T∞ and Tc,i. Consequently, an iterative process is necessary to calculate these heat flows and various local average temperatures. The first step in this process requires a calculation of the approximate adiabatic film cooling effectiveness achieved over the film cooled, external surface. One method whereby this initial guess may be achieved is via the use of a correlation that requires knowledge of the approximate film blowing ratio and film hole pitch; Bradley discusses several such correlations [25]. Using the definition of adiabatic film cooling effectiveness (equation 20), this permits the corresponding adiabatic wall temperature, Taw , to be predicted where the coolant temperature at the exit of the film hole (Tc,e) is approximated by the coolant temperature at the inlet of the double-wall geometry (Tc,i) as a first guess.