A three-dimensional model of polydisperse reactive sedimentation is developed by means of a multilayer shallow water approach. The model consists of a variety of solid particles of different sizes and densities, and substrates diluted in water, which produce biochemical reactions while the sedimentation process occurs. Based on the Masliyah–Lockett–Bassoon settling velocity, compressibility of the sediment and viscosity of the mixture, the system of governing equations is composed by non-homogeneous transport equations, coupled to a momentum equation describing the mass-average velocity. Besides, the free-surface depicted by the total height of the fluid column is incorporated and fully determined through the multilayer approach. A finite volume numerical scheme on Cartesian grids is proposed to approximate the model equations. Numerical simulations of the denitrification process exemplify the performance of the numerical scheme and model under different scenarios and bottom topographies.

中文翻译：

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多分散反应沉积的多层浅水模型


通过多层浅水方法开发了多分散反应沉积的三维模型。该模型由各种不同尺寸和密度的固体颗粒和稀释在水中的基质组成，在发生沉降过程的同时会产生生化反应。基于 Masliyah-Lockett-Bassoon 沉降速度、沉积物的压缩性和混合物的粘度，控制方程组由非齐次输运方程组成，并与描述质量平均速度的动量方程耦合。此外，通过多层方法合并并完全确定了由液柱总高度描述的自由表面。提出了笛卡尔网格上的有限体积数值方案来近似模型方程。反硝化过程的数值模拟例证了数值方案和模型在不同场景和底部地形下的性能。