| The labyrinth seal of the turbine cavity system of aero-engine has many functions,such as adjusting the cooling air flow of each chamber and preventing the hot gas from entering the disk cavity which will affect the working life of the turbine disk.In the process of aero-engine operation,the labyrinth seal will be deformed because of thermal stress and structural stress.The seal clearance will change along with the labyrinth’s deformation.This will affect the flow and temperature field of disk caviity in turn.A model was established which based on a high pressure turbine disk cavity system of an aeroengine in this paper.Using multifield coupling ways which based on the platforms of ANSYS Workbench software to get the change rules of seal clearance and the influence of seal clearance change on the temperature field of the disk cavity system.The model of one-way thermal fluid solid coupling analysis of high pressure turbine rotor disk cavity system was established by combining CFX module and Static Structure module to find out the thermal fluid and structural field in the disk cavity system under typical working conditions.The one-way coupling analysis couldn’t reflect the change rules of seal clearance under a full engine operation and the influence of seal clearance change on the temperature field of disk cavity.Therefore,the two-way coupling analysis model of engine was established by combining CFX module and Transient Structure module.The change rules of seal clearance under transient cycle condition were obtained by using the two-way coupling analysis.At the same time,the effect of seal clearance variation on the temperature field and structure field of the disk cavity system was obtained.Through the simulation of the two different multifield coupling ways,the rules of seal clearance under different speed and full transient process were obtained.It was found that the seal clearance decreased as the engine speed increased.The maximum variation could reach 5 times of the original clearance value.In the full transient process of the engine,the clearance of seal decreased first and then increased.Its speed of the change was different in different periods.At the same time,under typical engine conditions,the results of one-way coupling analysis can be used to make a fast prediction of the change of the seal clearance of the labyrinth directly.Two-way coupling analysis method was used to analyze the flow,temperature and stress deformation field of turbine cavity system according to the change of seal clearance.The results showed that the flow and temperature field of the disk cavity were greatly affected when the clearance of the seal decreased continuously.When deformation and interference of the labyrinth seal and case occured,labyrinth seal had little influence on the flow and temperature field of the disk cavity.In addtion,the two multifield coupling methods had a large difference in temperature and stress field the of the turbine disk due to the transient heat conduction.The results of the difference in the overall deformation and deformation distribution of the turbine disk were relatively small. |
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