Scramjet Isolator Shock-Train Leading-Edge Location Modeling
Document Type
Conference Proceeding
Publication Date
4-11-2011
Abstract
A dynamic model of the relationship between the back pressure and the shock-train leading-edge location is useful in the development of a shock-train leading-edge automatic control algorithm. In this research, several models were created relating the back pressure within an isolator to a shock-train leading-edge location. An isolator analog was mounted in a direct-connect, cold-flow, Mach 1.8 wind tunnel. Back pressure was created within the analog isolator using an adjustable ramp mounted in the downstream portion of the test section. All the models approximate a Hammerstein model in structure and include a static nonlinear polynomial model as well as a dynamic model. While the same static polynomial is used for all models, the dynamic models considered include simple continuous models, Auto-Regression with eXogenous variables (ARX) models, and Nonlinear ARX (NARX) models. Model development was accomplished using post-processed data with three of the models implemented and tested experimentally in a real-time (1 kHz) algorithm. All three models were able to predict the location of the shock-train to within one duct height and could, potentially be used for control algorithm development. The ARX and the NARX models returned comparable results in the real-time trials.
Source Publication
17th AIAA International Space Planes and Hypersonic Systems and Technologies Conference 2011
Recommended Citation
Hutzel, J., Decker, D., & Donbar, J. (2011, April 11). Scramjet isolator shock-train leading-edge location modeling. 17th AIAA International Space Planes and Hypersonic Systems and Technologies Conference. 17th AIAA International Space Planes and Hypersonic Systems and Technologies Conference, San Francisco, California. https://doi.org/10.2514/6.2011-2223
Comments
Co-author J. Hutzel was an AFIT PhD candidate at the time of this conference. (AFIT-DS-ENY-11-19, December 2011)