Investigation of Flame Driving and Flow Turning in Axial Solid Rocket Instabilities
Abstract
An understanding of the processes responsible for driving and damping acoustic oscillations in solid rocket motors is necessary for developing practical design methods that eliminate or reduce the occurrence combustion instabilities. While state of the art solid rocket stability prediction methods generally account for the flow turning loss, the magnitude and characteristics of this loss have never been fully investigated. This report describes results of an investigation of the role of the flow turning loss in the stability of solid rockets and its dependence upon motor design and operating parameters. A one dimensional acoustic stability equation that verifies that the flow turning loss term is appropriately included in the one dimensional stability formulation was derived for a chamber with a constant mean temperature and pressure by an approach independent from that of Culick. This study was extended provided the background and expressions needed to guide an experimental study of the flow turning loss in the presence of mean temperature and density gradients. This allows the study of combustion systems in which mean temperature gradients and heat losses are significant. The relevant conservation equations were solved numerically for the experimental configuration in order to predict the behavior of the flow turning loss and to assist in the analysis of experimental results. Experiments performed, with and without combustion, showed that the flow turning loss strongly depends upon the propellant burning rate and the location of the flow turning region relative to the standing pressure wave.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 31, 1993
- Accession Number
- ADA271066
Entities
People
- Ben T. Zinn
- Brady R. Daniel
- Lawrence M. Matta
Organizations
- Georgia Tech