摘要
针对全三元离心叶轮流线曲率法反命题设计,提出了一种求解S2m流面速度梯度方程的新型有限差分解法。该方法将相对速度沿准正交线的方向导数采用前向差分格式,将相对速度沿流线的方向导数分解为两项,一项采用前向差分,另一项采用后向差分格式,其他各参量沿准正交线或流线的方向导数统一采用前向差分格式。这样便解决了简单采用前向差分格式或后向差分格式难以保证求解速度场的矩阵主对角线元素占优问题,使求解格式具有较强的稳定性和收敛性。新型有限差分求解方法应用于Krain叶轮的改型设计,经计算流体动力学(CFD)分析得,改型叶轮效率提高约0.3%,压比提高约0.2,表明利用新型有限差分法求解S2m流面速度梯度方程是可行的。
For the streamline curvature inverse proposition design of a full three-dimensional centrifugal impeller, a new finite difference method is put forward to solve the S2m stream surface velocity gradient equation. In the difference scheme, forward difference is chosen for the relative velocity derivative along the quasi orthogonal curve~ that along the streamline direction is decomposed into two items, forward difference is used for first item, backward difference for another, and forward difference for all other parameter derivatives. The scheme solves the difficulty to guarantee the matrix main diagonal elements being dominant in solving velocity field with simple forward difference or backward difference scheme, and has higher stability and convergence. The new finite difference scheme is taken to redesign Krain impeller. The CFD analysis shows that modified impeller efficiency is increased by 0.3%, and compression ratio is heightened 0.2.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2015年第3期11-13,49,共4页
Journal of Xi'an Jiaotong University
基金
陕西省自然科学基金资助项目(2013JM7006)
关键词
有限差分法
S2m流面
流线曲率法
反命题
全三元叶轮
finite difference
S2m stream surface
streamline curvature
inverse proposition
full three-dimensional centrifugal impeller
