Open AccessQuantitative analysis of flow structures in compression ramp based on flow visualization
Author(s) -
Wu Yu,
Shihe Yi,
HsiaoYi Lin,
Pengcheng Quan,
Yangzhu Zhu
Publication year - 2015
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.64.014703
Subject(s) - intermittency , boundary layer , laminar flow , flow visualization , flow (mathematics) , mechanics , wind tunnel , blasius boundary layer , boundary layer thickness , fractal , physics , turbulence , mathematical analysis , mathematics
Flow visualization studies on the laminar boundary layer flows over a 25° compression ramp are carried out via NPLS technique in a Mach 3.0 wind tunnel; fine flow structures such as boundary layer, shear layer, and shock waves may be visualized clearly. Based on the visualized data, quantitative analysis is conducted using intermittency, spatial correlations, and fractal theory. The intermittency function γ of the boundary layer and the interaction region is calculated, and the size of coherent structures and the structure angle θ for the boundary layer are obtained, so that the fractal dimension of the boundary layer in streamwise can be provided. Experimental data in the present paper have been compared with the results of Ringuette and Bookey, and the quantitative characteristics of flow structures are discussed in detail.