Internal Flow and Axial Thrust Balancing of a Rocket Pump

Abstract

Internal flow of a cryogenic rocket turbopump is rather complicated compared to ordinary pumps. In order to design and predict characteristics of the axial thrust balancing system, analyses of the internal flow system is essential. In the present study, the calculation method for analyzing the internal flow system taking into account effects of boundary layer conditions and angular momentum change in chambers is applied. The characteristic of an axial thrust balancing system, which is comprised of a balance piston and grooves on the stationary wall, was evaluated. Calculated results showed that the system has a wide self-balancing range and is suitable for rocket turbopumps.

Unsteady response of flow system around balance piston in a rocket pump

“…First of all, to verify that the present model could achieve balance at proper positions, the steady-state calculation by this model was carried out and compared with the results of the steady analysis of the internal §ow [3]. Figure 4 shows static axial thrust characteristics of balance piston.…”

“…This chamber model is not able to treat the pressure distribution inside the chamber, although the balance piston chamber has the radial pressure distribution. In this model, the equivalent radial pressure drop estimated by the integration of the pressure distribution, which is calculated by steady analysis of the internal §ow [3], is given to this chamber model by the function component (2). The downstream path of ori¦ce #2 is expressed by a simple model (chamber, restriction and tank component).…”

“…In the previous studies [2,3], the axial thrust characteristics were calculated by in-house one-dimensional (1D) §ow analysis code, which takes account of momentum transported into the chambers and the boundary layer. In this code, it is assumed that the §ow is steady and incompressible.…”

“…The analysis code developed with this theoretical analysis was applied to investigate the axial thrust characteristics [2,3]. Della Gatta et al [4] investigated the axial thrust balance by steady computational §uid dynamics (CFD) analysis.…”

Parametric study of different fins for a rocket at supersonic flow

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] Several techniques had been used to investigate the flow field near a WAF including free-flight gun tests, wind-tunnel tests (with and without the aid of pressure sensitive paint), and computational fluid dynamics (CFD). The USAF also investigated several methods of reducing the magnitude of the induced roll by slotting WAFs and altering the fin-body junction angle.…”