Experimental and Numerical Investigation of Cryogenic Jet Atomization

Abstract

Unerstanding the complex environment of the rocket combustion chamber involves a good unerstanding of the injection phenomena. This understanding allows the rocket designer to employ time and cost saving modeling tools to better design a higher performing rocket engine. The rocket engine performance is highly dependent on the injection processes within the chamber. This project looked at injection processes in the supercritical regime of the injected fluid, cryogenic nitrogen, in order to better understand realistic conditions in the rocket engines of today. The investigation considers test conditions from 4.0 to 6.0 MPa at two different injection velocities and temperatures. Experimental data taken by Raman imaging and shadowgraphy are compared to computational models for these various test conditions. The test data allow comparisons of density, potential core length, length scales and jet spread angle. The results validate the computational models fairly well. This agreement allows further research to use the models to predict injection behavior under these operating conditions. Further comparisons were made between the various test cases using the computational models considering the effects of pressure, Velocity and temperature variations on the cryogenic jet.