Direct formulation of bipropellant thruster performance for quantitative cold-flow diagnostic

Chihiro Inoue, Yuki Oishi, Yu Daimon, Go Fujii, Kaname Kawatsu

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


We present a straightforward formulation predicting the characteristic velocity and specific impulse for bipropellant thrusters as a direct function of injection conditions, propellant combination, and nozzle expansion ratio. The theoretical formulation deduces a framework for a quantitative noncombustion test or cold-flow test to predict the performance indices. We simply employ water and dyed water as simulant liquids and then measure the local ratios of mixture and flow rate using an absorbance spectrometer. Density ratio mismatch between hypergolic propellants and water can be reasonably convertible. Combined with chemical equilibrium analysis, we obtain characteristic velocity and specific impulse across wide injection mixture ratios. The validity of the quantitative water-flow diagnostic is evidenced by comparing the results with those of corresponding combustion tests using nitrogen tetroxide and monomethylhydrazine as the propellants under several injector unlike-doublet and triplet configurations, showing that the mixing states of bipropellant thrusters under combustion can be reproduced using the water-flow diagnostic.

Original languageEnglish
Pages (from-to)842-849
Number of pages8
JournalJournal of Propulsion and Power
Issue number6
Publication statusPublished - Nov 2021

All Science Journal Classification (ASJC) codes

  • Aerospace Engineering
  • Fuel Technology
  • Mechanical Engineering
  • Space and Planetary Science


Dive into the research topics of 'Direct formulation of bipropellant thruster performance for quantitative cold-flow diagnostic'. Together they form a unique fingerprint.

Cite this