Terfous Abdelali, Chiban Samia, Ghenaim Abdellah
a Fluid Mechanics, ICUBE Laboratory , INSA Strasbourg Graduate School of Science and Technology , Strasbourg , France.
b Civil Engineering Department , Tishreen University , Latakia , Syria.
Environ Technol. 2016 Aug;37(15):1865-74. doi: 10.1080/09593330.2015.1135988. Epub 2016 Feb 16.
This paper presents a two-dimensional model to study the sediment deposition from marine outfall jets. The introduced unidirectional coupling (fluid-sediment) is an appropriate choice in the case of low-concentrated particle-laden jets such as municipal wastewater discharge, where the concentration of particles is small enough and does not affect the hydrodynamic development of the jet in the nearfield. The sedimentation model takes advantage of the preferential concentration phenomenon. The deposition criterion states that the deposition of sediments begins when the vertical component of the entrainment velocity becomes smaller than the settling velocity. Once the deposition process begins, it is controlled by the settling velocity, entrainment velocity, volume flux, and sediment concentration. The deposition along the jet trajectory is expressed by an ordinary differential equation coupled with the liquid phase equations. Experiments of Lane-Serff and Moran [Sedimentation from Buoyant jets. J Hyd Eng. 2005;131(3):166-174], Cuthbertson and Davies [Deposition from particle-laden, round, turbulent, horizontal, buoyant jets in stationary and coflowing receiving fluids. J Hydr Eng. 2008;134(4):390-402], and Lee [Mixing of horizontal sediment laden jets [dissertation]. Hong Kong: University of Hong Kong; 2010], chosen from bibliography, are used to validate the model. These experiments cover the cases of horizontal and inclined buoyant jets in stationary ambient, horizontal buoyant jets in co-flow current and nonbuoyant horizontal jets in stationary ambient. Good agreement between the experiments and the obtained simulations is revealed.
本文提出了一个二维模型来研究海洋排污口射流的沉积物沉降。对于低浓度含颗粒射流，如城市污水排放，引入的单向耦合（流体-沉积物）是一个合适的选择，其中颗粒浓度足够小，不会影响近场射流的水动力发展。沉积物沉降模型利用了优先浓度现象。沉积准则表明，当夹带速度的垂直分量小于沉降速度时，沉积物开始沉积。一旦沉积过程开始，它就由沉降速度、夹带速度、体积通量和沉积物浓度控制。沿射流轨迹的沉积由一个常微分方程与液相方程耦合表示。从参考文献中选取的Lane-Serff和Moran[浮力射流的沉积物沉降。《水利工程杂志》。2005年；131(3):166-174]、Cuthbertson和Davies[在静止和同流接收流体中含颗粒、圆形、湍流、水平、浮力射流的沉积。《水利工程杂志》。2008年；134(4):390-402]以及Lee[水平含沙射流的混合[论文]。香港：香港大学；2010]的实验用于验证该模型。这些实验涵盖了静止环境中水平和倾斜浮力射流、同流中水平浮力射流以及静止环境中非浮力水平射流的情况。实验结果与模拟结果显示出良好的一致性。
