Effects of chemical reaction caused by cooling stream on film cooling effectiveness

With the increase of inlet temperature of gas turbines, the benefits by using the conventional methods are likely to approach their limits. Therefore, it is essential to study novel film cooling methods for surpassing these current limits. Based on the theory of heat transfer enhancement, a film cooling method with chemical reaction by cooling stream is proposed. In order to test the feasibility of the proposed method, numerical simulations have been conducted. The classic flat plate structure with a 30 degree hole is used for the simulation. In the present study, the effects of the parameters in relation to the chemical reaction on film cooling effectiveness, such as chemical heat sink, volume changes, and reaction rate, are investigated numerically. The conventional film cooling is also calculated for the comparison. The results show that film cooling effectiveness is improved obviously due to the chemical reaction, and the reaction heat and reaction rate of cooling stream have an important effect on film effectiveness. However, the effect of volume changes can be ignored.