Development of Methods to Predict High-Speed Reacting Flows in Aerospace Propulsion Systems

Abstract

This paper discusses the current state-of-the-art of computational capabilities for predicting reacting flows in high-speed aerospace propulsion systems with an emphasis on the flow fields in scramjets. We begin with a review of the history of efforts to model the scramjet environment and then concentrate on more recent activities that lead to today's capabilities. The NASP technology program provided strong motivation for advancing the computational capabilities of the country in both the government and private sectors. Required ground test facilities with sufficient test times were limited to around Mach 8, and higher Mach numbers, achievable in pulse facilities, could only be maintained for the order of milliseconds. In addition, the number of facility cycles available to parameterize a given engine flow path were limited, and the facilities were expensive to operate. Computational capabilities were needed to fill both of these gaps. While the NASP program was not successful in developing a vehicle, it did spawn the development of new computational algorithms. The Hyper-X Program beginning in 1995 revived high-speed computational research and development. A flight program is the catalyst that drives technology development and synthesizes all of the efforts into a unified tool for development of the ultimate experiment, the flight of a hypersonic vehicle. The genesis of most of the current day state-of-the-art computational tools for scramjet research and development began with this program. This paper attempts to cover this story from NASP and Hyper-X to the present day.

Development of zone flamelet model for scramjet combustor modeling

“…However, the non-intrusive optical techniques still can only provide planar or zonal flowfield information, the three-dimensional flow structures as well as their evolution physics cannot be revealed solely by the measurements. From this point of view, high-fidelity numerical modeling is almost the only way to gain deep and comprehensive insights into the internal flow, mixing and combustion processes in scramjet combustors [6][7][8].…”