关键词: 离心叶轮;参数化;不完全敏感性;优化设计

Abstract: According to the limitation of the traditional optimization design method for centrifugal impeller, the optimization method for low specific speed centrifugal pump impeller based on incomplete sensitivities is proposed. In this method, the affection of the control parameters perturbation on the flow state variation can be neglected while calculating the gradient of the design objective function with the control variable of the impeller passages shape. So the flow filed only need to be simulated once in one optimization cycle, it avoids the calculation of the flow field repeatedly in finite difference method. It also avoids deducing and solving the adjoint equation in adjoint method. Therefore, the calculation cost is greatly reduced. The calculation case is the low specific speed centrifugal impellers; the two dimensional blade is parameterized by Taylor expansion. The coefficients in the Taylor function are taken as the control variable. The moment acting on the blade are considered as the objective function. Using the incomplete sensitivities method the gradient of the objective function with respect to the control variable can be evaluated easily, and the blade shape can be renewed according to the inverse direction of the gradient vectors. The optimum design of impeller can be achieved while the objective function is minimized. The calculation case results show that the proposed incomplete sensitivities theory for the optimization of low specific speed centrifugal impeller is rational.

Key words: centrifugal impeller;parameterization;incomplete sensitivities;optimum design