| Thermal barrier coatings(TBCs)have become an indispensable technology for high-performance aero-engines.They can significantly reduce the metal temperature of components and increase the life of components.They have been widely used in military,civil aviation engines and industrial gas turbines.in.The thermal barrier coating’s thermal insulation effect is related to the blade cooling channel design,cooling air flow adjustment,strength and even the ultimate service performance of the blade components.There are many factors that affect the thermal insulation effect of TBCs,such as service environment and cooling structure.Based on the fluid structure coupling finite element method,this paper studies the influence of thickness of TBCs,gas and cold air parameters,and gas film hole location on the thermal insulation effect of TBCs,reveals the influence law qualitatively and quantitatively,and provides guidance for the design of blade structure and profile.The specific research contents and results are as followsFirstly,based on the NASA report,this article first established a threedimensional turbine blade with thermal barrier coating and film holes and the external flow field,and performed meshing to set appropriate boundary conditions,and used the SST turbulence model for fluid-structure coupling calculations.Comparing the calculated results with the NASA experiment report,it is found that there is a higher consistency,thus verifying the feasibility of the model.Based on this model,the influence of thermal barrier coatings with thicknesses of 0.3 mm,0.4 mm,and 0.5 mm on the thermal insulation effect of turbine blade coatings with film holes is studied.The results show that the thickness of the coating is positively correlated with the thermal insulation effect of the coating in the research range,that is,the thicker the coating,the better the thermal insulation effect.Each increase of 0.1mm in the thickness of the thermal barrier coating can reduce the alloy temperature by an average of 34 K.Secondly,the influence of gas temperature,gas flow,air-conditioning temperature,and air-conditioning flow on the heat insulation effect of the thermal barrier coating of the turbine blade with film holes is studied under the service environment.The results show that the cooling efficiency of TBCs increases with the increase of the temperature and flow of the gas cooling air;the heat insulation effect decreases with the increase of the gas temperature and the cooling air temperature,and increases with the increase of the cooling air flow and the gas flow.The blades are in different places.There are different heat insulation effects.The thermal barrier coating can insulate 27 K on average for every 400 K increase in gas temperature.When the gas flow rate increases by 0.1kg/s,the average heat insulation of TBCs is 19 K.Every time the temperature of the cold air drops by 300 K,the thermal barrier coating can insulate by 40 K.Each increase of 0.02kg/s TBC of cold air flow can heat insulation 25 K on average.Thirdly,by changing the different positions of the air film holes on the leading edge,pressure surface,and suction surface of the turbine blades,through numerical simulation of fluid-solid coupling heat transfer,the influence of different air film hole positions on the thermal insulation effect of TBCs is obtained.The results show that the position of the air film hole in the turbine blade directly affects the corresponding heat insulation effect.The closer the air film hole is to the leading edge,the greater the impact on the thermal insulation efficiency of TBCs.The air film hole near the trailing edge has a greater impact on TBCs.The effect of heat insulation is small.Air film holes should be located as close to the leading edge as possible,and unnecessary air film holes should be reduced at the trailing edge. |
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