Subjects: Dynamic and Electric Engineering >> Engineering Thermophysics submitted time 2018-02-01 Cooperative journals: 《工程热物理学报》
Abstract: The unsteady flow field of the counter-rotating axial flow compressor (CRAC) under design condition was time accurately simulated, the unsteady effects between every rotor and guide vane were analyzed, which contains the guide vane/rotor interaction and rotor/rotor interaction. The results indicate that the unsteady mass flow on the interface of two rotors fluctuates stronger than the other two interfaces, so the unsteady interaction between two rotors is the strongest in the CRAC. The unsteady flow field at typical height was analyzed; combined with the unsteady fluctuation intensity, the further design and mechanism of the CRAC was investigated. The unsteady fluctuation intensity increases with the flow direction, the axial distance between the second rotor and the outlet guide vane (OGV) is so short that the unsteady fluctuation intensity at the inlet of the OGV is the strongest.
Subjects: Dynamic and Electric Engineering >> Engineering Thermophysics submitted time 2017-05-24 Cooperative journals: 《工程热物理学报》
Abstract:为了增加间断Galerkin(Discontinuous Galerkin, DG)方法在非定常流动中的求解效率,本文开展了非定常流动的隐式DG方法研究。隐式DG方法的构造采用二阶向后差分格式(BDF2)进行时间项离散,非线性代数系统的求解基于Newton迭代法,采用块对称Gauss-Seidel(SGS)迭代法对线性方程组进行了求解。基于所发展的非定常流动的隐式DG方法,分别对等熵圆柱扰流和卡门涡街(Re=100)现象进行了数值模拟。研究结果表明,所发展的隐式DG方法能够达到设计精度,能够在高出显式方法两个数量级的时间步长上保持稳定,具有高的求解效率,且计算结果与显式方法和相关文献均吻合较好。