The effect of Knudsen number Kn on the similar characteristics between different scale film cooling flow and heat transfer was numerically studied. Single-row plate cylindrical hole film cooling models with aperture of 0.3

3

10mm were selected. Cooling effectiveness and discharge coefficient of models under condition of different Kn and the same Kn were calculated. Results show that small and large hole models have similar flow and heat transfer characteristics under the same value of Kn

resulting in little differences between cooling effectiveness and discharge coefficient. When Kn varies

the flow and heat transfer characteristics of these two models are different

bringing about different cooling effectiveness and discharge coefficients. Therefore it is necessary to make sure that small and large hole models should have the same Kn in similar amplification experiment of film cooling.