Planar wall plumes are gravity-driven flows where a fluid of lower (or higher) density than the ambient rises (or lowers) along a vertical or inclined wall. This study investigates planar wall plumes at five different wall slopes, ranging from a vertical wall (θ=90°) to a shallow inclination of θ=3°, using highly resolved direct numerical simulations. The three-dimensional turbulent structure of these supercritical flows is investigated in detail along with the streamwise evolution of the depth-averaged quantities. Simulations were performed in very large domains in order to focus attention on the behavior of the plumes in the near self-similar state, far downstream of the inlet. In the self-similar state, key quantities such as the entrainment rate, the basal drag coefficient, the Richardson number (or equivalently the Froude number), and the shape factors reach constant values, which dependent only on the slope. The present simulations, along with earlier results for subcritical currents at shallower slopes, provide a complete description of this dependency.

中文翻译：

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由垂直和倾斜表面界定的平面壁羽流

平面壁羽流是重力驱动的流动，其中密度低于（或高于）环境的流体沿着垂直或倾斜的壁上升（或下降）。本研究使用高分辨率直接数值模拟研究了五种不同墙坡度的平面墙羽流，范围从垂直墙 (θ=90°) 到 θ=3° 的浅倾斜度。详细研究了这些超临界流的三维湍流结构以及深度平均量的流向演化。在非常大的域中进行模拟，以便将注意力集中在入口下游远处的近自相似状态下的羽流行为。在自相似状态下，夹带率、基础阻力系数、理查森数（或等效的弗劳德数）和形状因子等关键量达到恒定值，仅取决于斜率。当前的模拟以及较浅斜率的亚临界电流的早期结果提供了这种依赖性的完整描述。