The use of Bezier polynomial patches to define the geometrical shape of the flow channels of compressors

Abstract

Based on the method of Casey (1), the present paper makes further development in using Bezier polynomial patches to define the geometrical shape of the flow channels of compressors. There are two advantages in this new method. First, in the geometrical construction process the blade profile and the contour of impeller's meridional channel can be given by the same number of patches of the same degree so as to avoid more complicated repeat computations. Second, for curved surface construction there are no restrictions of linearity in the spanwise direction in order to match the distribution of flow angles at the inlet better and to fit the needs of various load models. Some examples have shown that the shapes produced by Bezier polynomial patches are general enough to be used in the design of new compressors and in approximation of the geometry of existing ones. The method is particularly suitable for incorporation into a computer-aided design procedure.