%0 Journal Article %T Flow Characteristics of Two-Dimensional Supersonic Under-Expanded Coanda-Reattached Jet %A Tetsuji Ohmura %A Toshihiko Shakouchi %A Shunsuke Fukushima %A Koichi Tsujimoto %J Journal of Flow Control, Measurement & Visualization %P 1-14 %@ 2329-3330 %D 2021 %I Scientific Research Publishing %R 10.4236/jfcmv.2021.91001 %X When there is a wall near the jet, it deflects and flows while being attached to the wall owing to the Coanda effect. The flow characteristics of the incompressible and two-imensional (2D) Coanda-reattached jets have been considerably explained. However, 2D supersonic under-expanded jets, reattached to side walls, have not been sufficiently investigated. These jets are used in gas-atomization to produce fine metal powder particles of several micrometers to several tens micrometers. In this case, the supersonic under-expanded jets are issued from an annular nozzle, which is set around a vertically installed circular nozzle for molten metal. The jet flow at the center cross-section of the annular jet resembles a 2D Coanda-reattached jet that deflects and attaches on the central axis. In this study, the flow characteristics of a supersonic under-expanded Coanda air jet from a 2D nozzle that reattaches to an offset side wall are elucidated through experiment and numerical analysis. For numerical analysis, we show how much it can express experimental results. The effects of supply pressure P0 on the flow characteristics such as the flow pattern, size of shock cell, reattachment distance, and velocity and pressure distributions, etc. are examined. The flow pattern was visualized by Schlieren method and the velocity distribution was measured using a Pitot tube. These results will be also useful in understanding the flow characteristics of a gas-atomization annular nozzle approximately. %K Supersonic Flow %K Under-Expanded Jet %K Coanda Reattached Jet %K Flow Visualization %K Gas-Atomization %K Experimental Analysis %K Numerical Analysis %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=105702