Research On The Application Of Non-axisymmetric Structure In Sector Cascade Under Distorted Condition

The development of advanced gas turbine technology is an important part of the country,s future development plan,and also an important means to enhance the comprehensive national strength and international competitiveness.How to make the gas turbine work smoothly,safely and efficiently in various working environments is a problem that needs to be paid attention to in the development of advanced gas turbine technology.In the development of advanced gas turbine technology,how to make the gas turbine work smoothly,safely and efficiently in various working environments is a problem that needs to be paid attention to.In recent years,the flow deterioration caused by the distorted inlet of the engine has attracted more and more attention.Inlet total pressure distortion will cause comer separation and comer stall,and cause the reduction of compressor performance and stability,Improving and optimized the flow of compressor flow passage with axisymmetric structure,to obtain a better performance and stability of the compressor stage has a high theoretical significance and engineering value.In this paper,the sector cascade designed by the research group is taken as the research object,and the influence of non-axisymmetric stator and non-axisymmetric fence cases on the flow field of the stator passage under distorted inlet condition is studied by means of numerical simulation.Firstly,producing a distorted condition at the inlet of stator cascade by rotating an inlet guide vane,after comparing and analyzing the influence of distortion on the flow field of stator cascade,a variety of non-axisymmetric stator cases including positive bowed,negative bowed,forward swept,back swept and various combinations of bowed and swept are set at the locations where seriously affected by inlet distortion,then explore the mechanism of influence on stator passage of non-axisymmetric stator modeling cases.After that,a best stator case of non-axisymmetric is selected to use in combination with different non-axisymmetric fence cases,to investigate the influence on the distorted flow field of the combined axisymmetric structure case.The research results show that,the negative bowed cases can reduce the comer separation and optimize the flow in the flow passage which are badly affected by the inlet distortion.the best case of negative bowed can reduce the loss in the flow passage which has a severe loss by 12.93%and the loss is reduced by 2.75%of overall flow field.The forward swept case can achieve a better effect in reducing root loss.Although the back swept case is not as effective as the forward sweep in improving root loss,it has a better effect in reducing overall loss of the flow passage.After the combination of stator bowed modeling and swept modeling,most combination cases can optimize the flow at the root of the stator.Combined modeling cases have a good inheritance of the effect of bowed and swept,and the appropriate combination case can achieve a good effect in reducing the loss at most height of stator.The optimal case of the combined case can reduce the loss of the passage which has a severe loss by 14.61%,and the loss of the overall passage is reduced by 3.24%.On the basis of the best non-axisymmetric stator case,A appropriate fence case can block the transverse secondary flow at the endwall,and the airflow at root can be bent better along the flow passage.but the flow loss will increase after adding the non-axisymmetric fence case.