%0 Journal Article
%T Application of Rainbow Schlieren Deflectometry for Jets from Round Laval Nozzles Followed by Cylindrical Ducts
%A Ryota Fukunaga
%A Muhammad Minarul Islam
%A Yusuke Awata
%A Shinichiro Nakao
%A Yoshiaki Miyazato
%J Journal of Flow Control, Measurement & Visualization
%P 15-27
%@ 2329-3330
%D 2021
%I Scientific Research Publishing
%R 10.4236/jfcmv.2021.92002
%X The jet from a round Laval nozzle followed by a cylindrical duct with an inner diameter of 10 mm and a length of 50 mm is investigated experimentally. The Laval nozzle has a design Mach number of 1.5. Quantitative flow visualization of the jet issued from the duct exit is performed over a range of nozzle pressure ratios from 2.0 to 4.5 using the rainbow schlieren deflectometry combined with the computed tomography to investigate the jet three-dimensional structure. The flow features of the near-field shock systems in the jets are displayed with the density contour plot at the cross-section including the jet centerline. Effects of the nozzle pressure ratio on the density profile along the jet centerline are clarified quantitatively. In addition, a comparison between the present experiment and the previous one with a conventional Laval nozzle for jet centerline density profiles is carried out to examine the effect of the cylindrical duct. Furthermore, the three-dimensional structures of overexpanded and underexpanded jets are demonstrated with the isopycnic surfaces to visualize the internal flow features.
%K Rainbow Schlieren Deflectometry
%K Jet Flow
%K Shock Wave
%K Computed Tomography
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=108108