Experimental and numerical study of impingement on an airfoil leading edge with and without showerhead and gill film holes

This experimental investigation deals with impingement on the leading edge of an airfoil with and without showerhead film holes and its effects on heat transfer coefficients on the airfoil nose area as well as the pressure and suction side areas, a comparison between the experimental and numerical results are also made. The tests were run for a range of flow conditions pertinent to common practice and at an elevated range of jet Reynolds numbers (8000-48,000). The major conclusions of this study were: (a) The presence of showerhead film holes along the leading edge enhances the internal impingement heat transfer coefficients significantly, and (b) while the numerical predictions of impingement heat transfer coefficients for the no-showerhead case were in good agreement with the measured values, the case with showerhead flow was under-predicted by as much as 30% indicating a need for a more elaborate turbulence modeling.