This study reveals that injecting a light fluid of density ${\rho }_b$ in the recirculating bubble of a bluff body at $\text{Re}\approx 6.4\times {10}^4$ has a greater drag reduction potential than blowing fluid of a density greater than or equal to that of the free stream $\rho$. It is found that the maximum drag reduction scales as ${({\rho }_b/\rho )}^{-\frac{1}{6}}$. This power law combines the ability of the recirculating bubble to diffuse the injected momentum and the effectiveness of the injection to increase the recirculating bubble length.

中文翻译：

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通过以各种气体密度进行底吹来减少三维物体的阻力。

这项研究表明，注入密度较小的轻质流体 ${\rho }_b$ 在虚张声势的身体的循环泡沫中 $\text{回覆}\approx 6.4\times {10}^4$ 与吹制密度大于或等于自由流的流体相比，具有更大的减阻潜力 $\rho$。发现最大减阻比例为${（{\rho }_b/\rho ）}^{-\frac{\mathrm{1个}}{6}}$。该幂定律结合了再循环气泡扩散注入的动量的能力和注入效果以增加再循环气泡的长度。