Parametric Design And Numerical Research Of Trailing Edge’s Cooling Structure Of Gas Turbine

Gas turbine has been widely used in the field of aviation, ship and power industry. With the development of the society, gas turbine technology is also in constant development, one of the important solution to improve the performance of gas turbine which was increasing the inlet temperature, but it leaded to a new problem that was temperature far more the blade material can bear. In order to ensure normal operation of gas turbine, advanced cooling technology must be used.On one hand, blade trailing edge cooling is limited by the narrow space and have the characteristics of high temperature and stress concentration, so the cooling structure which need attaches great importance is difficulty to design. On the other hand, the process of cooling blade design is the iteration that design-proofread-improve, it need modify and optimize persistently. It certainly will waste lots of time and energy, so it is necessary to come up with an efficient design method.In order to improve design efficiency, parametric design and optimize platform of cooling structure was designed in this paper. The thought of the patform mianly iclude the following points: firstly, dividing cooling blade to different parts, secondly, analysizing characteristic parameters about each part, thirdly, having a clear train of thought and the implementation processa bout parametric process, fourthly, write Matlab and NX secondary development program to achieve parametric process and modeling function, finally, invoke secondary develo-pment program in the base of the platform. This platform will help decreasing design cost impressively and improving the design efficiency.Firstly, parametric design method of trailing edge slot, wedge slit, circle-shaped column, water drop-shaped column, swirling structure and weave structure were proposed and established in this paper. Secondly, four types of combined cooling blade with different trailing edge’s cooling structure which are the following: trailing edge slot with circle or water drop-shaped column, swirl structure and weave structure was designed in the base of a certain gas turbine first stator blades which include film hole, impact opening, rib and division plate cooling structures through the parametric platform. Finally, four combined cooling blade were aero-thermal coupling numerical calculated and analysing the cooling mechanism of structure. Due to the effect of compound cooling techniques, the temperature of blade comply with the design requirements except root of blade trailing edge which exist small part area of high temperature in the situation of two types of pin fin group structures. Compared with circle-shaped column, water-drop shaped column structure’s pressure loss coefficient is lower about 42.9%, have lower total pressure of the second cavity’s cooling gas inlet and higher mass flow in film hole of second cavity. Circled-shaped column structure has stronger ability of heat transfer because the effect of horseshoe vortex and passage vortex, but integrated heat transfer coefficient in water-drop shaped column structure is higher about 47.07%, so watershaped has higher application value.Compared with pin-fin structure, swirl and weave structures have higher pressure drop coefficient and lower mass flow of trailing edge, there are more mass flow outflow from gas hole of second cavity. The order for heat transfer ability are impact of channels, swirl chambers and contractive channels in swirl structure. Swirl chambers make longitudinal vortex flow, staggered arrangement impact of channels make flow mixing sufficient after impact, the above factors enhance heat transfer ability of swirl structure. Compared to swirl structure, temperature in suction surface of blade weave trailing edge decrease and the area of low temperature increase. Length and area of the flow channels increase because of bending properties, flow channels constantly meet and separate leads to complex vortex system and sufficient mixture, all above help strengthening heat transfer inside weave channels. Heat transfer ability is uniform in the direction of span and flow about weave structure which has more application value.The results in this paper have a reference function for the design and study of cooling blade.