Numerical study of a novel monolithic heat exchanger for electrothermal space propulsion

F Romei,A Grubisic

doi:10.1016/j.actaastro.2019.03.025

Abstract

Fully-coupled multiphysics simulations are applied to investigate a number of candidate heat exchanger materials in the Super-High Temperature Additively-Manufactured Resistojet (STAR) thruster. Two mission applications are considered: a low earth orbit (LEO) primary propulsion application and a secondary reaction control system (RCS) application of an all-electric geostationary (GEO) telecommunications platform. High-temperature operation provides a significant increase in specific impulse over the state-of-the-art Xenon-resistojets. Inconel 718 is investigated for moderate-performance for LEO applications, while pure tantalum and pure rhenium are examined for the extreme temperature high-performance GEO application. Simulations determine the attainable performance including heat transfer, Navier-Stokes continuum flow and Joule heating physics in both transient and steady state. Nozzle efficiency, heat exchanger efficiency, electrical characteristics and other key performance indicators are explored.

Highlights

Electric spacecraft propulsion has been in development since the 1960s, with numerous high-value telecommunications satellites carrying electric propulsion, performing combined electric orbit raising and station-keeping functions
A new possibility has emerged for geostationary (GEO) platforms, whereby all-electric systems is augmented by utilising hightemperature xenon (Xe) resistojets for the reaction control system (RCS) [1]
High-temperature xenon resistojets could improve the existing performance of state-of-the-art Xe resistojet thrusters used as primary propulsion for low earth orbit (LEO) spacecraft [3, 4]

Summary

Introduction

Electric spacecraft propulsion has been in development since the 1960s, with numerous high-value telecommunications satellites carrying electric propulsion, performing combined electric orbit raising and station-keeping functions. This combined application has been termed all-electric and presents a highly mass efficient solution for telecoms spacecraft. A new possibility has emerged for geostationary (GEO) platforms, whereby all-electric systems is augmented by utilising hightemperature xenon (Xe) resistojets for the reaction control system (RCS) [1]. On all-electric spacecraft, RCS systems still require hazardous hydrazine propellant in a separate independent secondary propulsion system, presenting significant cost increase and integration complexity. A xenon resistojet, operating in parallel with an all-electric system from a common propellant, would remove the requirement for hydrazine systems [2]. High-temperature xenon resistojets could improve the existing performance of state-of-the-art Xe resistojet thrusters used as primary propulsion for low earth orbit (LEO) spacecraft [3, 4]

Methods

Results

Conclusion