The Space Shuttle Main Engine High-Pressure Fuel Turbopump Rotordynamic Instability Problem Academic Article uri icon

abstract

  • The SpaceShuttle main engine high-pressure fuel turbopump has been subject to a rotor dynamic instability problem, characterized by large and damaging subsynchronous whirling motion. The original design of the pump (from a rotor dynamic viewpoint) and the evolution of its subsynchronous whirl problem are reviewed. The models and analysis which have been developed and utilized to explain the instability and improve stability are also reviewed. Elements of the rotordynamic model which are discussed in detail include the following: (a) hydrodynamic forces due to seals, (b) internal rotor damping, (c) bearing and casing support stiffness asymmetry, and (d) casing dynamics. The stability and synchronous response characteristics of the following two design alternatives are compared: (a) a 'stiff' symmetric bearing support design and (b) a damped asymmetric stiffness design. With appropriate interstage seal designs, both designs are shown, in theory to provide substantially improved stability and synchronous response characteristics in comparison to the original design. The asymmetric design is shown to have better stability and synchronous response characteristics than the stiffly supported design. (A)

author list (cited authors)

  • Childs, D. W.

citation count

  • 63

publication date

  • January 1978