Evaluation of Air Injection in a Sudden Expansion Diffuser for Real-Time Afterburning Application
Abstract
Altitude testing of advanced hydrogen-fueled propulsion systems will require techniques to deal with unburned hydrogen in the engine exhaust stream. One approach is real-time afterburning. This approach would inject oxidizer in the test facility exhaust diffuser and burn off the excess hydrogen before it reached any facility machinery. A combined experimental and computational study was conducted to evaluate the feasibility of this approach. The experimental study tested a sudden expansion diffuser with injection both upstream and downstream of the step. Engine air was delivered through either a Mach 3.0 or 0. 8 nozzle The acquired data evaluated mixing of the nonreacting streams using measured temperatures and a Crocco relationship. Wall and pitot pressures were used to evaluate diffuser performance. The PARC computer programs was used to predict the flow field two test conditions. The results showed that good mixing can be obtained with the configuration at penalty of loss in maximum diffuser pressure rise. The PARC program did an excellent job of predicting the flow-field pressures and shock structure; however, it was less satisfactory for predicting mixing based on temperature distribution.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1991
- Accession Number
- ADA230850
Entities
People
- S. E. Stephens
Organizations
- Arnold Engineering Development Complex