Turbopumps, a Historical Perspective

Abstract

A turbopump (abbreviated as TP) is a high precision, high speed, relatively complex piece of rotary machinery, where a turbine drives one or two liquid propellant pumps. It is a key component in many major liquid propellant rocket engine (LPREs) and its function is to raise the pressure of liquid propellants, taken from the tanks in a flight vehicle, and feed them under pressure into the thrust chamber(s) of a rocket engine. This paper traces the technical history of turbopumps from the first units developed by Professor Robert H. Goddard in the 1934 up to efficient modern units with power levels up to 250,000 horsepower. This high shaft speed, accurately balanced assembly of high precision rotating machinery is a key component of a pump-fed rocket engine and is dramatically different from all the other rocket engine major components. The historical sequence of various alternate turbopump configurations, the increases in pump discharge pressure and turbine power, clever new features, and different design approaches are described. The key turbopump design issues (strength, critical speed, vibrations, materials, cavitation, size, or weight) and components (pump impellers, inducers, seals, turbine blades or bearings) are included Special features include the Soviet start-turbine, radial-in-flow turbine, or booster-turbopumps. Examples of turbopumps from different countries are given and their development organizations are cited.