Experiments on Liquid Hydrogen Turbopump for Rocket Engine

Abstract

The development of LH₂/LOX rocket engine is being conducted in Institute of Space and Aeronautical Science, University of Tokyo. This paper describes the liquid hydrogen turbopump for rocket engine. The turbopump was designed to feed liquid hydrogen into the thrust chamber of 7, 000kg thrust level, and has the capabiliites of head rise of 5, 900m and flowrate of 2.90kg/sec at the rated rotational speed of 44, 000rpm. The pump is a single-stage, centrifugal-flow type with a helical inducer and a single volute casing. The impeller of the pump, 130mm in diameter, consists of 24 blades with a discharge angle of 90 degrees. The axial thrust loaded on pump shaft is balanced by decreasing the pressure behind the impeller to an adequate level with the aid of 24 small radial vanes. The pump is driven by a single-stage impulse turbine.
Tests were performed in Noshiro Testing Center of ISAS since August in 1977 and the performance characteristics and the functions of the pump were verified through 14 runs up to date. The tests showd that the pump satisfied the design specifications. The results are summarized as follows;
(1) the head coefficient of the pump is 0.64 at the rated flowrate,
(2) the distribution of pressure in the volute is less than 10% of the mean value,
(3) the pump works without stall under the condition of negative NPSH, although the performance is deteriorated to some extent.