FullText URL Experim_Fluid_56_211.pdf
Author Kouchi, Toshinori| Goyne, Christopher P.| Rockwell, Robert D.| McDaniel, James C.|
Abstract Schlieren imaging is particularly suited to measuring density gradients in compressible flowfields and can be used to capture shock waves and expansion fans, as well as the turbulent structures of mixing and wake flows. Conventional schlieren imaging, however, has difficulty clearly capturing such structures in long-duration supersonic combustion test facilities. This is because the severe flow temperatures locally change the refractive index of the window glass that is being used to provide optical access. On the other hand, focusing-schlieren imaging presents the potential of reduced sensitivity to thermal distortion of the windows and to clearly capture the flow structures even during a combustion test. This reduced sensitivity is due the technique’s ability to achieve a narrow depth of focus. As part of this study, a focusing-schlieren system was developed with a depth of focus near ±5 mm and was applied to a direct-connect, continuous-flow type, supersonic combustion test facility with a stagnation temperature near 1200 K. The present system was used to successfully visualize the flowfield inside a dual-mode scramjet. The imaging system captured combustion-induced volumetric expansion of the fuel jet and an anchored bifurcated shock wave at the trailing edge of the ramp fuel injector. This is the first time successful focusing-schlieren measurements have been reported for a dual-mode scramjet.
Keywords Shock Wave Turbulent Structure Stagnation Temperature Fresnel Lens Shock Cell
Note This is an Accepted Manuscript of an article published by SPringer
Published Date 2015-11-18
Publication Title Experiments in Fluids
Volume volume56
Issue issue12
Publisher Springer
Start Page 211
ISSN 1432-1114
NCID AA10447762
Content Type Journal Article
language 英語
OAI-PMH Set 岡山大学
File Version author
DOI 10.1007/s00348-015-2081-9
Web of Sience KeyUT 000366639800005
Related Url isVersionOf https://doi.org/10.1007/s00348-015-2081-9