SABRE预冷器计算模型及其在整机模型中的应用

预冷器的性能对SABRE等预冷组合循环发动机具有重要影响,为实现发动机方案设计阶段预冷器的快速设计与评估,建立了预冷器准二维快速评估模型。将SABRE预冷器的几何结构简化为一个扇环形区域,沿径向和周向将该区域划分为二维节点。应用守恒方程及传热关联式完成单个节点计算,再求解节点矩阵的平衡方程组,计算内外流体特定节点上参数的二维分布,得到预冷器出口参数。将模型嵌入发动机总体性能程序中,实现了发动机设计及非设计点的预冷器性能计算的功能。与文献数据对比结果表明,预冷器模型传热计算误差小于5%,摩擦阻力误差小于10%。整机计算结果显示,Ma0~5范围内,预冷器空气侧温降范围为143K至932K,温降随飞行马赫数升高单调上升。预冷器传热有效度范围为0.896-0.945,空气侧总压恢复系数范围为0.852-0.904。

SABRE Precooler Calculation Model and Its Application in Engine Model

The performance of the precooler has a significant influence on precooled combined cycle engines like SABRE. In order to realize the rapid design and evaluation of the precooler in the engine design phase, a quasi-two-dimensional rapid assessment model of the precooler was established. The geometric structure of the SABRE precooler is simplified into an annular sector area, which is divided into two-dimensional nodes in the radial and circumferential directions. Conservation equations and heat transfer correlation equations are used to calculate one node, and then solving the balance equations of the node matrix to calculate the two-dimensional distribution of the parameters at the specific nodes of the internal and external fluids, and the outlet parameters of the precooler are obtained. The model was embedded in the engine performance program, and the function of precooler performance calculation at the engine design and off-design points were realized. The results of comparison with literature data show that the model deviations of heat transfer are within 5%, and the deviations of friction is within 10%. The engine simulation results show that in the range of Ma0~5, the air side temperature drop of the precooler ranges from 143K to 932K, and it increases monotonously with the flight Mach number increasing. The range of precooler effectiveness is 0.896-0.945, and the range of air side total pressure recovery coefficient is 0.852-0.904.