微尘沉积形貌对冲击气膜冷却结构换热特性影响的数值研究

When air containing the dust enters the aero-engine，the dust is easy to deposit on the internal wall of the turbine blade. In order to explore effects on heat transfer characteristics of internal wall with the dust deposition，the impingement and film cooling channel were chosen. Depending on the result of the dust deposition experiment，the dust deposition morphology consisting of conical-shaped convex and the ring-shaped convex was built. Nusselt number on the impingement target surface under different jets Reynolds number is achieved by numerical simulation. The result shows that the average Nusselt number of wetted area weakens dramatically when the dust deposits on the impingement target surface，but average Nusselt number of mapped area is affected slightly. The high heat transfer area around the impingement stagnation point decreases. Nusselt number of the high heat transfer area near the middle point of adjacent jet holes is improved. In addition，the heat transfer intensity of the impingement target surface is improved with the increasing jets Reynolds number. The backflow vortices near the wall increase due to the disturbing effect of the conical-shaped convex and the ring-shaped convex，which cause the increasing thickness of the temperature boundary layer in most areas of the impact target surface. Therefore，the heat transfer performance decreases.