Drag reduction analysis of counterflow jets in a short penetration mode

초록

The characteristics around counterflow jets are difficult to predict, because of the many variables involved. To analyze counterflow jets with different freestreams, a numerical simulation was conducted, by solving a two-dimensional axisymmetric RANS equation. The trends in drag reduction were reviewed in short penetration mode, with freestream conditions (altitude: 10 to 19 km, M-infinity: 2.0 to 4.0). According to the results of the numerical analysis, it was determined that the differences in overall flow structure arise from the freestream Mach number. The recirculation zone is the key feature of the flow. In the flow mechanism, the recirculation zone is affected by the velocity and pressure at the boundary, and the position and pressure of the reattachment point are the main parameters influencing the recirculation zone. Observed differences in the flow structure depending on the freestream Mach number can be explained by these parameters. As a result, different drag reduction curves can be drawn for each freestream Mach number, and a maximum value on drag reduction exists. (C) 2020 Published by Elsevier Masson SAS.

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