Geometric generating method of blade profiles on arbitrary rotary flow surfaces

Generally, flow surfaces are reduced to planes, cylindrical surfaces or conical surfaces in traditional blade profile design method. A blade profiles geometric design method on arbitrary rotary flow surfaces is presented. In this method, blade's profiles are generated by traditionally distributing thickness along a camber line method. First, a camber line is generated on the flow surface. Points on the camber line are obtained by stacking point moving along meridional streamline at a distance and rotating circumferentially at the same time. The camber line is divided into series of segments, and arrays of points on flow surface are acquired. Then, thickness on each point is distributed, obtaining pressure line and suction line. Based on the assumptions of the symmetry of pressure and suction line about camber line at the leading edge and trailing edge point, a leading edge and trailing edge generating method is presented. After an elliptical or circular leading edge and trailing edge is created, by adjusting the position and tangent vector of the starting point and end point of suction line and pressure line, G1 continuity at junction points can be guaranteed. A blade geometric modeling system has been developed using MFC and NX8.0. The goal of generating blade profiles on arbitrary rotary flow surfaces is achieved. Compared with airfoils generating on conical surfaces, airfoils generated by this method is closer to airflow trend in flow passage. ©, 2015, AAAS Press of Chinese Society of Aeronautics and Astronautics. All right reserved.