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_∞: 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.

由于涉及许多变量，因此很难预测逆流喷嘴周围的特性。为了分析具有不同自由流的逆流射流，通过求解二维轴对称RANS方程进行了数值模拟。在短时穿透模式下，在自由流条件下（高度：10至19 km，_M∞：2.0到4.0）。根据数值分析的结果，确定总体流动结构的差异是由自由流马赫数引起的。回流区是流动的关键特征。在流动机制中，再循环区受边界处的速度和压力影响，并且重新连接点的位置和压力​​是影响再循环区的主要参数。这些参数可以解释根据自由流马赫数所观察到的流动结构差异。结果，可以为每个自由流马赫数绘制不同的减阻曲线，并且存在减阻的最大值。