基于反问题的涡轮过渡流道一体化支板设计方法

Integrated Design of Intermediate Turbine DuctUsing Inverse Method

关键词:  大涵道比涡扇发动机  涡轮过渡流道  支板  一体化设计  反问题

Key words:  High bypass ratio turbofan engine  Intermediate turbine duct  Strut  Integrated design  Inverse problem

摘要:

为进一步改善大涵道比涡扇发动机气动性能及燃油经济性，降低其污染物排放，控制其重量与成本，提出了一种高效的高、低压涡轮过渡流道整流支板一体化设计理念，即对原型支板与第一级低压涡轮导叶进行初步正问题一体化设计，并基于气流角全三维粘性反问题进行进一步改型设计，使得在保证自身气动性能不降低的基础上，带一体化支板涡轮过渡流道能够与高、低压涡轮实现良好匹配。以某型发动机过渡流道为算例开展了一体化设计工作，并采用三维数值模拟方法进行了设计点、非设计点流场分析评估。结果表明，设计点工况下一体化支板出口气流角以及马赫数分布均与原型导叶出口一致，验证了一体化设计的有效性。同时，带一体化支板的过渡流道总压损失从原型流道的2.49%降低到了1.02%。而在非设计工况，带一体化支板的过渡流道气流分离明显减小，具有更宽的最佳工况范围。

Abstract:

In order to improve the aerodynamic performance of high bypass ratio turbofan engines, reduce the fuel consumption and emissions, limit the weight and cost, the efficient integrated design concept based on inverse method has been proposed for the intermediate turbine duct (ITD) between high pressure turbine and low pressure turbine. The design process has two parts: impose the integrated concept to the original struts and the following low pressure inlet guide vanes (IGV) to get the direct design; apply the flow angle-based 3D inverse method to the direct design to make a good match between the struts and the low/high pressure turbines, without degrading the aerodynamic performance. In the paper, this kind of integrated design method was exerted to a type of ITD, before the calculation of flow field was conducted on both design point and off-design point. The results validate the design of integrated ITD as the exit flow angle and Mach number of the integrated ITD show great agreement with the original ones. The total pressure loss of the new ITD is 1.02% at design point, compared with 2.49% of the baseline ITD. Furthermore, at off-design points, the flow separation in integrated ITD is significantly reduced, extending the range of optimum conditions.