Research On Flow And Heat Transfer Characteristics Of Cross-rib And Trailing Edge Split Joint Structure

The most effective way to improve the output power and cycle efficiency of the gas turbine is to increase the initial temperature of the turbine inlet.With the increase of the initial temperature of the gas turbine turbine year by year,the heat resistance limit of the existing metal materials is far lower than the temperature of the working environment of the turbine blades.Therefore,in order to ensure the service life of the turbine blades,it is urgent to improve the cooling performance of the turbine blades.Because the trailing edge of the blade is thin and the space is narrow,it is easier to burn out,so more efficient cooling is required.The traditional internal cooling of the trailing edge of the turbine blade adopts the cooling method of the trailing edge column rib,and the cross rib is a special internal cooling structure.Compared with the ordinary cooling structure,the heat transfer is stronger and the structural strength is higher;the half-split cooling structure is to protect the trailing edge of the blade by forming a cold air film on the trailing edge of the turbine blade.Therefore,the composite structure of the cross rib and the trailing edge split seam has a good prospect.The main content of this paper is to use the fluid mechanics calculation software ANSYS CFX to conduct a numerical simulation study on the composite structure of the cross rib and split slit in a certain type of turbine blade,to explore the influence of multiple parameters on its flow and heat transfer,and to compare the cross rib and straight rib.Acting on the trailing edge of the blade is a comprehensive comparative analysis to evaluate the performance of the two.The main work is as follows:1.The geometric modeling and numerical simulation of the composite structure of the cross-rib and split-slot composite structure at the trailing edge of the blade are briefly described,and the correct turbulence model is selected with reference to the relevant literature,and the flow heat transfer of the composite structure of the cross-rib and the split-slot is analyzed according to the results of the numerical simulation.characteristics,including the flow structure and enhanced heat transfer mechanism in the cross-rib channel,the flow field characteristics of the split slit outlet and the distribution characteristics of the film cooling.The results show that the large-scale forced longitudinal vortices produced by the corners of the cross-rib sidewalls are the root cause of the heat transfer enhancement.2.A detailed study is made on the influence of basic geometric factors on the composite cooling structure of the cross rib and the trailing edge splitting slot,and the resistance coefficient,heat transfer performance,and comprehensive thermal efficiency of different blowing ratios,rib inclination angles,channel density and lip thickness are investigated.and film cooling efficiency.The results show that smaller rib inclination,sparser channel density and thinner lip can achieve better comprehensive heat transfer effect.3.In view of the fact that the cross rib has higher structural strength than the column rib,it has a certain potential to be used in the trailing edge of the blade to replace the traditional column rib.The film cooling efficiency of the surface of the turbine blade trailing edge and the heat transfer capacity of the internal channel,the drag coefficient in the channel and the comprehensive thermal efficiency are used to evaluate the performance of the two cooling structures,and to verify that the cross-rib and straight-rib structures are used in the blade tail The advantages brought by fate.The results show that the cross rib acting on the blade trailing edge has better heat transfer efficiency.