| The film cooling gas as a kind of protection means were widely used in gasturbine blade. Because of the complexity of the internal flow field of the gas turbine,many factors influence the effect of gas film-cooling, one major factor is the trail ofstatic leaves from spread. Static leaves make the freedom trail produce not stable flowvelocity and temperature fields periodically, and then to effect film-cooling of blade.,so the unsteady wake to move leaves film cooling effect of the gas has importantsignificance.This paper adopts SST k-ω turbulence model based on SIMPLE algorithm anddiscretizes the control equation using finite volume method. Firstly, the influence ofunsteady wake on film-cooling of blade, heat transfer and flow field around of bladehave been studied, got the path chart of cooling, gas jet film cooling efficiency map,Nusselt number distribution and flow field instantaneous turbulent kinetic energyfigure, through comparison analysis, we found that：The increasing of blow ratio willchange the flow condition, make jet occurred to the blade tip rotation and direction,improving speed will heighten jet spinning, and even change the flow direction；Withthe increasing of blow ratio, film-cooling efficiency nearby jet hole increases, butfilm-cooling efficiency of downstream film hole reduces, the speed increaseaccelerated mixing of jet and the mainstream, improve the gas film hole around thecooling efficiency, but in n=2000rpm, the area around of the third row-cooling holeeffect weakens, blow ratio increasing makes the surface heat transfer enhancementoverall, but the effect of speed on heat exchange is more complicated, heat transfer ofpressure surface is better when M=1.0, and suction surface’s heat transfer is betterwhen n=500rpm；The increasing of blow ratio enhances the turbulence of flow fieldnearby film hole, speed increasing leads to turbulence aggravate in the channelbetween blade sharp, and pneumatic loss bigger. Upstream wake swept blade at a certain frequency, so physical parameters offlow field and blade surface change periodically. Through the study of isothermalfigure、turbulent kinetic energy instantaneous map、Mach number and heat transfercoefficient graph figure in different time of a period, got a conclusion：During thetime from0.5T to1.0T, gas film cooling temperature is lower and covers a wide area,cooling effect at0.9T is best；The changing of turbulent kinetic energy、 the Machnumber and the heat transfer coefficient is not great in the whole periodic, turbulentkinetic energy larger value is in the first row of concentrated near the jet and leavestrailing edge place of blade, the Mach number is larger at0.7T time between thechannel rotating blade and static blade, the heat transfer coefficient near jet hole ofpressure side is higher, and the heat coefficient at the middle suction face is bigger,but reduced in the trailing edge. |
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