TY - GEN
T1 - Transverse jet mixing in a supersonic grid turbulence
AU - Kouchi, Toshinori
AU - Iwachido, Masaki
AU - Nakagawa, Takahiro
AU - Nagata, Yasunori
AU - Yanase, Shinichiro
N1 - Funding Information:
This work was supported by Innovative Science and Technology Initiative for Security, ATLA, Japan.
Publisher Copyright:
© 2020, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.
PY - 2020
Y1 - 2020
N2 - Turbulence grids were applied to Mach 2 supersonic wind tunnel to increase turbulence in a mainstream. We measured wall pressure, velocity by Laser Speckle Velocimetry (LSV) using acetone condensation nanoparticle and density by acetone Planer Laser Induced Fluorescence (PLIF). In this study, the test section has 12 mm width and 10 mm height at the exit of the nozzle and the turbulence grids, which consisted of tungsten wires having sub-mm diameter, was installed at the exit of the nozzle. Combination of the wire grid and tunnel wall expansion increased mainstream turbulence without flow unstart in the test section flow. In the case with 0.4-mm-diameter grid at 3 by 3 arrangement having a blockage of 21% of the nozzle exit area, the mainstream turbulence reached 8% of the mainstream velocity. Nitrogen gas was perpendicularly injected into the grid-generated supersonic turbulent flow and it mixing performance was investigated by using acetone-PLIF. Installation of the wire grid affected not only mainstream turbulence but also wall-bounded flow, resulting in thickening boundary layer. As a result, jet penetration increased with installing the wire grid. However, no remarkable improvement of the jet mixing was observed with installing the wire grid.
AB - Turbulence grids were applied to Mach 2 supersonic wind tunnel to increase turbulence in a mainstream. We measured wall pressure, velocity by Laser Speckle Velocimetry (LSV) using acetone condensation nanoparticle and density by acetone Planer Laser Induced Fluorescence (PLIF). In this study, the test section has 12 mm width and 10 mm height at the exit of the nozzle and the turbulence grids, which consisted of tungsten wires having sub-mm diameter, was installed at the exit of the nozzle. Combination of the wire grid and tunnel wall expansion increased mainstream turbulence without flow unstart in the test section flow. In the case with 0.4-mm-diameter grid at 3 by 3 arrangement having a blockage of 21% of the nozzle exit area, the mainstream turbulence reached 8% of the mainstream velocity. Nitrogen gas was perpendicularly injected into the grid-generated supersonic turbulent flow and it mixing performance was investigated by using acetone-PLIF. Installation of the wire grid affected not only mainstream turbulence but also wall-bounded flow, resulting in thickening boundary layer. As a result, jet penetration increased with installing the wire grid. However, no remarkable improvement of the jet mixing was observed with installing the wire grid.
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U2 - 10.2514/6.2020-2040
DO - 10.2514/6.2020-2040
M3 - Conference contribution
AN - SCOPUS:85092362743
SN - 9781624105951
T3 - AIAA Scitech 2020 Forum
BT - AIAA Scitech 2020 Forum
PB - American Institute of Aeronautics and Astronautics Inc, AIAA
T2 - AIAA Scitech Forum, 2020
Y2 - 6 January 2020 through 10 January 2020
ER -