Injection of Fluids into Supercritical Environments

Abstract

This paper summarizes and compares the results of systematic research programs at two independent laboratories regarding the injection of cryogenic liquids at subcritical and supercritical pressures, with application to liquid rocket engines. Both single jets and coaxial jets have been studied. Cold flow studies provided valuable information without introducing the complexities of combustion. Initial studies utilized a single jet of cryogenic nitrogen injected into a quiescent room temperature nitrogen environment with pressures below and above the thermodynamic critical pressure of the nitrogen. Later, the work was extended to investigate the effects of a co-flowing gas. Parallel to this work, combustion studies with cryogenic propellants were introduced to understand high pressure coaxial injection phenomena with the influence of chemical reaction. Shadowgraphy and spontaneous Raman scattering were used to measure quantities such as growth rates, core lengths, turbulent length scales, fractal dimensions, and jet breakup regimes. It is found that jets injected at supercritical pressures do not atomize as they do at subcritical pressures. Rather, they behave in many respects like variable density turbulent gas jets.

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Document Details

Document Type
Technical Report
Publication Date
Sep 02, 2004
Accession Number
ADA426295

Entities

People

  • A. Schik
  • J. Hussong
  • J. J. Smith
  • M. Oschwald
  • R. Branam

Organizations

  • German Aerospace Center

Tags

Communities of Interest

  • Energy and Power Technologies
  • Ground and Sea Platforms
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Acoustic Waves
  • Air Force
  • Boundary Layer
  • Chemical Reactions
  • Combustion
  • Creep
  • Critical Temperature
  • Heat Transfer
  • High Pressure
  • Lasers
  • Mechanical Properties
  • Propellants
  • Raman Scattering
  • Refractive Index
  • Rocket Engines
  • Scattering
  • Turbulent Mixing

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.