Development of Ultra-Low Specific Speed Centrifugal Pumps Design Method for Small Liquid Rocket Engines

Abstract

With the growth of the satellite industry, the demand for a propulsion system for small launch vehicles and spacecraft has increased. Small liquid rocket engines may require Ultra-Low specific speed centrifugal pumps due to the low required thrust and volumetric flow rate and high combustion chamber pressure. Therefore, in this study, a design method of Ultra-Low specific speed centrifugal pumps for several hundred Newton class small liquid rocket engines was developed by combining various empirical formulas. In addition, centrifugal pump impellers were designed using the Stepanoff method, which is typically used in pump design, and the circular arc method. The most appropriate method for designing Ultra-Low specific speed centrifugal pumps was determined through a comparative analysis with other methods and validated through CFD. As a result, the pump designed using the proposed method exhibited a performance of pumping and suction superior to the Stepanoff method. Although the number of arcs did not considerably influence the pump performance, the single arc method was confirmed to be the most appropriate design approach in terms of the design productivity and simplicity.

Keywords

• liquid rocket engine
• centrifugal pump
• ultra-low specific speed
• circular arc method
• Stepanoff method