Investigation of water jet break up by supersonic rocket exhaust

Abstract

In the testing of today’s rocket engines, both on large scale vertical test stands and smaller subscale horizontal component testing stands, it is extremely important to accurately be able to quantify and mitigate the thermal and acoustic loads the engines will generate on test stand infrastructure. Due to the large number of parameters that must be considered for many cases, development of a multi-phase computational code is under way in order to properly analyze and design water spray cooling systems used at NASA’s Stennis Space Center and across other NASA centers. A better understanding of the behavior and optimization of these systems would lead to a decrease in the cost of new systems and increase in the reliability of systems currently available. As such, a subscale test facility is being developed at Louisiana State University to provide experimental results which can be used to inform the development and verify the validity of such a code. The interaction of a supersonic jet of air with one or more water jets is examined and characterized using several non-intrusive diagnostic methods; focusing color Schlieren photography as well as laser sheet visualization is used obtain qualitative information about air jet and water breakup characteristics and phased doppler particle anemometry is used to gain point-wise statistical information about water particle size and velocity. In addition, work towards the transition to the examination of a combusting flow case using a scaled hybrid rocket engine will be presented.