Laminar separation bubbles are one of the main critical aspects of flows at low Reynolds numbers in the range of ${10}^4–{10}^5$. The flow separates in the laminar regime, the turbulence developing inside the recirculation region enhances the momentum transport, and the flow can reattach. Models based on the Reynolds-averaged Navier–Stokes equations suffer two of main issues: the determination of the transition onset and the level of the pressure recovery downstream of the reattachment of the flow. A model addressing both issues is presented in this paper. It is based on the $\gamma$ transition model for the transition detection. The production of the turbulent kinetic energy $\kappa$ has been properly enhanced thanks to a correlation found between the necessary boosting of $\kappa$ and the intermittency function behavior within the bubble. The low-Mach-number and Reynolds-number flows around the Selig–Donovan 7003, Eppler 387, and NACA 0015 airfoils are analyzed. The results are compared to experimental data and large-eddy simulations available in the literature. The model can be applied to the analysis of an arbitrary airfoil without need of preliminary calculation of the transition point within the bubble.

层流分离气泡是低雷诺数范围内流动的主要关键方面之一 ${10}^4\mathrm{——}{10}^5$. 流动在层流状态下分离，再循环区域内形成的湍流增强了动量输运，并且流动可以重新附着。基于雷诺平均 Navier-Stokes 方程的模型存在两个主要问题：过渡开始的确定和流重新附着下游的压力恢复水平。本文提出了一个解决这两个问题的模型。它基于$\gamma$过渡检测的过渡模型。湍流动能的产生$\kappa$ 由于在必要的提升之间发现了相关性，因此得到了适当的增强 $\kappa$以及气泡内的间歇函数行为。分析了 Selig-Donovan 7003、Eppler 387 和 NACA 0015 翼型周围的低马赫数和雷诺数流动。将结果与文献中可用的实验数据和大涡模拟进行比较。该模型可应用于任意翼型的分析，无需初步计算气泡内的过渡点。