A numerical modeling of a swirling turbulent jet in a coflowing stream was carried out. The flow description involved two second-order mathematical models. The first one includes the averaged equations of motion and the differential equations for transfer of normal Reynolds stresses and dissipation rate in the thin shear layer approximation. The second model relies on the far wake approximation. The distances from the source of the jet in the calculations reached very large values. At small distances, the calculated profiles of the averaged velocity components agree well with the known experimental data from Lavrent’ev Institute of Hydrodynamics SB RAS. At large distances from the source, the flow becomes close to the self-similar one, with degeneration laws and normalized profiles consistent with the known theoretical concepts of the dynamics of swirling turbulent jets in a coflowing stream. The problem of asymptotic behavior of a nonswirling turbulent jet in a coflowing stream was also considered. A self-similar solution based on numerical experiments was obtained.

中文翻译：

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湍流射流中湍流射流演变的数学模型

对并流的涡流湍流进行了数值模拟。流程描述涉及两个二阶数学模型。第一个包括平均运动方程和在薄剪切层近似中传递法向雷诺应力和耗散率的微分方程。第二个模型依赖于远尾近似。在计算中，与射流源的距离达到非常大的值。在小距离处，平均速度分量的计算轮廓与Lavrent'ev水动力学研究所SB RAS的已知实验数据非常吻合。与来源的距离较远时，流量变得接近自相似流量，具有退化定律和归一化轮廓，与同流中涡流湍流的动力学理论原理相一致。还考虑了在涡流中无涡流的射流的渐近行为问题。获得了基于数值实验的自相似解。