符合NACA翼型特征的液力变矩器叶片厚度设计

Design strategy for blade thickness of hydraulic torque converter based on the characteristics of NACA airfoils

针对变矩器常用的基于等倾角射影定理的叶片厚度设计方法(简称为等倾角射影法)带来的叶片三维形态连续性差,以及变矩器效率和能容低下问题,提出符合美国国家航空咨询委员会(National Advisory Committee for Aeronautics,NACA)翼型特征的液力变矩器叶片厚度设计方法。通过定义NACA翼型函数的分段约束,使其符合液力变矩器的流固耦合要求,实现变矩器翼型函数系数的确定。根据翼型函数及直纹曲面规则分别得出叶片厚度值与法向加厚方向,从而得出液力变矩器叶片厚度矢量,实现叶片厚度的设计(简称法向加厚法)。以某型号双涡轮液力变矩器为参照对象,分别利用本方法与等倾角射影法建立模型,对比CFD仿真结果与台架试验结果可知,利用该方法有效地减少了叶片设计参数,设计出的水滴状叶片能够提高变矩器的效率,实现叶片的自动化设计。

In order to address the poor continuity of the three-dimensional blade morphology caused by the conventional design method that is based on the projection theorem for isoclinic angles,we present a strategy for designing the blade thickness of the hydraulic torque converter（ TC） with the characteristics of the National Advisory Committee for Aeronautics（ NACA） airfoil. By defining the subsection constraints of the NACA airfoil,the designed blade can meet the fluid-structure interaction requirements of the hydraulic TC,and confirm its airfoil function. In addition,based on the airfoil function and the rules for a ruled surface,we derived the blade thickness and normal thickening direction,and then obtained the blade thickness vector of the hydraulic TC,which realized the blades thickness design（ called the normal thickening method,for short）. Taking the blade design of the twin-turbine TC as an example,we used this method and the projective method for isoclinic angles to establish the model. By comparing the computational fluid dynamic（ CFD） simulation and rack test results,we found that by using the proposed method,the design parameters of the blades could be effectively reduced. The designed drop-like blades could improve the efficiency of the hydraulic TC,and an automatic blade design can be realized.WANG Anlin1 CAO Yan1 HAN Jibin2