Numerical Study on the Influence of the Trailing Edge Overflow Holes on the Flow and Heat Transfer of the Inner Cooling Passage on the Trailing Edge of the Turbine Blade

Abstract

In this paper, the influence of overflow outlet at the trailing edge of the turbine blade on the flow and heat transfer in the trailing edge cooling passage is studied by numerical simulation method. The influence of the number of overflow holes, overflow hole radius and overflow contact area of the overflow hole (change the number of holes and hole radius, and unchange the flow cross-sectional area) on the distribution of flow coefficient of the trailing edge overflow hole were compared. And the influence of the flow distribution from the trailing edge and the lower edge plate, the influence on the heat transfer of the inner cooling wall ware compared. The results show that the number, radius, and flow contact area of the trailing edge overflow hole have large influence on the distribution of the flow coefficient of the trailing edge overflow hole. The decrease of the number of holes, the increase of the hole radius, and the reduction of the flow contact area all make the flow coefficient of the edge overflow hole rises; Increase of the number of hole and hole radius both increase the outflow ratio at the trailing edge and increase the average heat transfer coefficient of the inner cooling passage. The overflow contact area of the overflow hole has little influence on the overflow outflow ratio and the average heat transfer coefficient.