Rocket Propulsion Elements, 9th Edition

CHAPTER 10TURBOPUMPS AND THEIR GAS SUPPLIES

10.1 INTRODUCTION

A turbopump (TP) is a high‐precision, high‐speed rotating machine usually consisting of a gas turbine driving one or two centrifugal pumps. Its purpose is to take propellants from the vehicle's tanks, raise their pressure, and deliver them into suitable piping systems. These pressurized propellants are then fed to one or more thrust chambers, where they are burned forming hot gases. A TP is a unique key component of all larger liquid propellant rocket engines with pumped feed systems. This chapter discusses various common types of TPs, describes major TP components, mentions some of their principal design issues, and outlines one design approach.

A well‐designed TP must deliver the intended propellant flows at the intended pump discharge pressures and mixture ratio, must have an acceptable reliability (e.g., it will not malfunction or fail during the flight duration), and will run at the highest practical energy efficiencies. Furthermore, TPs should not cause any significant vibration (in the engine or entire vehicle) nor should be adversely affected by externally caused vibrations, should function well under all operating conditions (such as different initial propellant temperatures, a range of ambient temperatures, start and stop transients, accelerations in the flight direction and other directions), and have the minimum practical inert TP mass. It is important for pumps not cavitate during operation because cavitation ...