In order to make clear the effect of wall curvature on full-coverage film cooling, an experimental study was further carried out using a concavely curved wall, having the same injection hole arrangement as that in the 1st report. The local mass transfer coefficient on the concave FCFC wall was precisely measured by means of the naphthalene sublimation technique with various blowing ration, M, and a non-dimensional injection temperature, θ. The mass transfer rate measured is considerably larger than that of the flat and the concave walls, owing to the effect of the centrifugal force on the trajectory and the spanwise diffusion of the secondary coolant. The constant calculated by the linear relationship between the Stanton number and θ is quantitatively in good agreement with the adiabatic cooling effectiveness obtained separately. As a result, it is found that the maximum reduction of heat transfer is obtained with M = 0.5, though the dependency of the heat transfer rate on M is weak. In addition, the mass transfer coefficient in the recovery flat wall downstream of the curved wall has been measured and discussed.
