Experimental Investigation Of Film Cooling Efficiency On Turbine Blade Leading Edge

The designed temperature of import operating on modern gas turbine is very high. It must be sophisticated to use cooling technology to keep the normal operation, and the rate of heat transfer is the highest on the leading edge. Therefore, in order to research the heat transfer characteristics of the film cooling on the leading edge of gas turbine in detail, it is very important to guide the engineering design, the method of experimental and numerical calculation was adopted in this paper.In order to study the heat transfer characteristics of turbine blade leading edge, this paper presents an experimental study of film cooling on the leading edge of a turbine blade. There are many factors influence on cooling effectiveness, such as blowing ratio, main flow Reynolds numbers investigated in detail. The experimental results show that cooling effectiveness enhances with the increase of blowing ratio in the downstream of film holes and declines with the increase of blowing ratio near holes; and the highest cooling efficiency is produced on the suction surface, the lowest film cooling efficiency is produced on pressure surface. On the suction surface, different Reynolds number has a little impact on cooling efficiency; on turbine blade leading edge, low blow ratios had little effect on cooling efficiency, the higher blow ratio is, the higher cooling efficiency near holes is.In this paper, numerical simulation was performed to investigate heat transfer characteristics of the leading edge of blade with three holes of filming-cooling, using Realizable k-εmodel. Two rows of holes were located in the suction side, and the other pressure surface. The difference on the cooling efficiency and heat transfer of the three rows of holes on the suction side and pressure side were analyzed, the heat transfer and film cooling effectiveness distribution in the region of leading edge are expounded under different blow ratio. The results show that the cooling efficiency of the downstream of film holes on the suction side and pressure side is higher, but the cooling efficiency on the suction side is higher than that on the pressure side; the cooling efficiency deteriorates with the increase of blowing ratio near holes, but improving in the downstream of film holes; high blow ratios resulted in high Nu , and the changes of Nu in the far immediately downstream are more obvious than near holes. Finally, numerical calculation results are compared with the experimental results, and the conclusion is in good agreement.