The Design Of The Variable Geometry Turbine Blade

The gas turbine not always work in the ideal design conditions,in a variety of operatingconditions, the gas turbine must have to have a good play to adapt to the requirements ofmodern production life. The principle of variable geometry turbine is adjusted depending onthe external environment geometric parameters such as the area of the turbine, the turbineperformance to be able to adapt to the requirements of different working conditions. Variablegeometry turbine design has a very real sense..Because of rear loading blade’s good angle of attack adaptability, in the variable geometryturbine blade design has been pade more attention. So rear loading blade also be researchedin this paper.This paper uses commercial fluid mechanics calculation software NUMECA to researchblade and its modification blade with the numerical simulation method. First, research thegeometric feature of rear loading blade, namely the relationship between arc and thicknessdistribution and blade load distribution. Then research the different loading blade with gapwith the numerical simulation method. Study the influence of load distribution on clearanceflow. The results of the study show that load moved can effectively reduce turbine leakageloss.The second is change of a certain type of gas turbine level4power turbine first level tothe loading modification, And modify the meridian expansion runner. Make it more adaptableto the requirements of the rotation, in does not affect the output power and efficiency of thepremise. Then after the modification of the blade on the variable geometry variable conditionof numerical simulation, analyzes its thermodynamic performance and aerodynamicperformance. The study found that the inlet unchanged, under the precondition of turbine forrotation efficiency will be reduced, and shut lobular will let low efficiency faster; In totalimports under the premise of constant temperature, improve the export and import of statictotal pressure to close small blade, reduce pressure and import export total pressure need toopen big blade. And turn down than up blade to blade cascade performance more influence.