Design Method and Numerical Simulation Analysis of Special-Shaped Centrifugal Impeller: Part I — Design Method

Abstract This paper presents the design method of the special-shaped centrifugal impeller based on the streamline curvature method. Some conclusions described in this article will be thoroughly analyzed and demonstrated in the second part. The second part mainly involves case analysis and numerical simulation of performance parameters. The design of a centrifugal impeller must yield blades that are aerodynamically efficient, easy to manufacture, mechanically sound, especially low noise during running. The blade shape is generated by specifying surface velocity distributions and consists of straight-line elements that connect points at hub and shroud. The new impeller changed the channel structure from the classic radial outflow to axial outflow and removed the U-shaped diffuser flow passage. At the same time, the anti-noise technology is applied to optimize the flow channel design. The theoretical comparison between the classic centrifugal impeller and the new impeller shows that, in the aspect of energy saving, the flow field distribution of the new impeller is more uniform, gas flow loss is significantly reduced and the compressor efficiency is obviously improved. In addition, due to the noise elimination characteristics of the distributed flow passage, the noise of the new impeller is obvious lower than the traditional centrifugal impeller. But due to the complexity of the flow channel form, the flow resistance of the flow channel will increase, however this resistance increase can be controlled by the flow channel design.