Schlieren measurements of shock train flow fields in a supersonic cylindrical isolator at Mach 2

Authors:
Open Access
Publisher website
Google Scholar
Abstract
In a supersonic cylindrical isolator at Mach 2, the structures and frequency characteristics of shock train flow fields were experimentally studied by the schlieren measurement method. According to the design principle of parallel light through schlieren windows in a cylindrical duct, a high-precision conformal optical window pair was designed and integratively processed before. Based on a self-built pipeline structure with conformal windows in a direct-connect wind tunnel under adjustable back-pressure conditions, the shock surfaces in a cylindrical isolator at Mach 2 were first captured by the schlieren method. Then, the schlieren photographs were corrected by a nonlinear image transformation algorithm for the restoration of real shock train structures, and the experimental results were compared with numerical simulation results quantitatively. Finally, the shock train positions were calculated by an image recognition algorithm to analyze the self-excited oscillation frequency characteristics of shock train structures. The methods and experiments in this study enriched optical observation methods of supersonic flows through non-rectangular cross-section isolators in scramjet. Graphical abstract
Funding Information
  • State Key Laboratory of High Performance Complex Manufacturing (Kfkt2020-07)
  • National Natural Science Foundation of China (No. 12102470)
  • NUDT Research Project (No. ZK20-05)
  • Innovative Research Group Project of the National Natural Science Foundation of China (12372298)

This publication has 35 references indexed in Scilit: