核心机驱动风扇级二维仿真模型与变循环发动机零维仿真模型耦合方法的研究

为了提高变循环发动机(VCE)零维仿真模型的可靠性和精度,建立了核心机驱动风扇级(CDFS)二维仿真模型,基于完全耦合方法,将CDFS二维仿真模型耦合于VCE零维仿真模型,发展了VCE多维度仿真模型,分析了VCE零维仿真模型与多维度仿真模型计算结果的差异,使用VCE多维度仿真模型,分析了CDFS气动参数径向非均匀分布对VCE性能的影响。结果表明,结合CDFS二维仿真模型对边界条件的要求,重新选取VCE仿真模型中的迭代变量和平衡方程,可以基于完全耦合方法建立VCE多维度仿真模型;与零维仿真模型相比,CDFS二维仿真模型考虑了部件几何参数等物理信息,可以为VCE循环参数分析提供更加真实的部件工作特性,并在功率平衡与流量平衡等条件的约束下引起其它部件工作点及VCE性能的变化;VCE零维仿真模型与多维度仿真模型所得推力的最大差异为2.99%;结合CDFS涵道比,可以将CDFS出口气动参数径向非均匀分布这一流动特性耦合到VCE循环参数分析中;VCE多维度仿真模型对迭代变量初值的选取提出了更高的要求,需要使用VCE零维仿真模型的解作为初值以保证收敛性。

An Investigation of Coupling Method Between Two-Dimensional Core Driven Fan Stage Model and Zero-Dimensional VariableCycle Engine Model

In order to improve the reliability and accuracy of the zero-dimensional variable cycle engine (VCE) model, the two-dimensional model of core driven fan stage (CDFS) was built and integrated into zero-dimensional VCE model with fully coupled approach and the multi-level VCE model was established finally. The differences of results between the zero-dimensional VCE model and multi-level VCE model were analyzed, and the effects of radial non-uniform distribution of aerodynamic parameters of CDFS on VCE performance was studied with the multi-level model. The result indicates that the iterative variables and balance equations need to be adjusted on the basis of the boundary conditions of two-dimensional CDFS model so as to establish the multi-level VCE model with fully coupled approach. Compared with the zero-dimensional CDFS model, the two-dimensional CDFS model containing the physical information such as geometric parameters can provide more practical and physical CDFS characteristics for VCE cycle analysis. The change of CDFS performance will lead to the change of working points of other components and VCE performance with constraint of the flow continuity and power balance. The maximum difference of thrust between the zero-dimensional VCE model and multi-level VCE model is 2.99%. Combining with CDFS bypass ratio, the radial non-uniform distribution of aerodynamic parameters of CDFS outlet can be integrated into VCE cycle analysis. More reasonable initial values for iterative variables are needed to solve the multi-level VCE model. Therefore, the result of the zero-dimensional VCE model is used to initialize the iterative variables of multi-level VCE model.