The appearance of air-cooled turbine makes the turbine front temperature of aero engine further increase, which promotes the rapid development of high performance aero engine. However, with the application of complex internal shock, enhanced heat transfer by turbulent flow, convection gas film, dense gas film spray and other cooling forms on turbine components, the interaction between cold air and gas becomes more and more complex. In order to quickly and accurately evaluate the coupling effects of flow and heat transfer on complex cooled turbine blades, a parametric modeling method is developed to perform high-fidelity geometric modeling and aerothermal coupling simulation for GE E3 high-pressure turbine first-stage guides. The analysis results show that the parametric modeling method can realize the high-fidelity geometric modeling of complex air-cooled turbine blades, and obtain high gas-thermal coupling calculation accuracy. At the same time, a large number of internal flow heat transfer details of turbine blades are obtained through detailed analysis, which can support the fine design of high temperature turbine blades.
Research background
With the continuous development of aero-engine technology, the turbine front temperature of the new generation of engines can be increased by 300-400K compared with the previous generation. At the same time, the allowable temperature increase corresponding to each generation of superalloy materials is only 30-50K. The gap between the two means that more complex internal and external cooling structures need to be used to ensure the safe operation of blades in high temperature environments. The complex cooling structure leads to more prominent problems in the matching of internal and external pressure and flow resistance of the blades. On the one hand, it is more urgent to carry out fine analysis and design of internal and external flow and heat transfer of turbine blades; on the other hand, it increases the difficulty of blade modeling and gas-thermal coupling analysis. Previously, in the field of engineering, a round of gas-thermal coupling analysis of turbine blades, including the details of the internal cavity and the film holes, was carried out. The cycle could reach about one month, and a lot of time was consumed in the modeling of turbine blades and the repair of geometric models. Therefore, the realization of parametric modeling of complex cooling blades is a necessary prerequisite for rapid iterative design, fine design and optimization of turbine blades.
Innovation of paper
Based on the refined design requirements of complex cooled turbine blades, this paper established a parameterized modeling method with strong engineering practicability, which can quickly and accurately achieve the geometric modeling of the inner cavity and shape of complex air-cooled turbine blades in about 1 minute, and greatly reduce the cycle and error rate of air-thermal coupling analysis of blades with complex cooling structures. Taking GE E3 high pressure turbine primary guide vane as an example, parametric modeling method is used to quickly reproduce the internal and external structural details of the guide vane according to literature data. On this basis, the gas-thermal coupling analysis of the turbine blade is carried out, and the flow and heat transfer characteristics of the blade containing a lot of details are obtained, and the improvement direction is proposed.
Summary and prospect
Parametric modeling is an effective means to achieve rapid performance evaluation of air-cooled turbine blades, which can quickly and accurately realize the geometric modeling of the inner cavity and exterior of complex air-cooled turbine blades, greatly improving the work efficiency of designers. The work in this paper shows that rapid generation of high-fidelity geometric models based on parametric modeling method and multidisciplinary coupling analysis of turbine blades are efficient means to quickly locate design defects of blades and carry out multidisciplinary design improvement. Focus on the public number: two machine power first, free access to a large number of two machine design data, focusing on two machine knowledge and key technologies!
At present, the parameterization work in this paper includes some of the most common internal and external cooling elements. With the development of cooling technology, more complex cooling elements will be applied to blades, so more geometric structure parametric modeling methods need to be developed modularly to expand the application range of parametric design tools in this paper. At the same time, it is also necessary to further combine the parametric modeling process with the rapid prediction of the flow heat transfer performance of various cooling elements, the selection of cooling structures, the rapid multidisciplinary analysis, and the standardized automated engineering drawing, so as to develop more practical multidisciplinary design tools.