Inclined dense jets are commonly used to mitigate the environmental impacts of brine discharge in coastal desalination plants. Numerous studies have been performed to numerically simulate the sophisticated structures of the flow within this process. However, numerical prediction of the process is still a challenge. The present paper performs a comprehensive numerical study using the large eddy simulation (LES) approach on inclined dense jets oriented at angles 15°, 30°, 45°, 60°, and 75°, with a particular emphasis on the near-wall region, where the most complicated structures of the flow occur. The objective is to evaluate the capability of the LES approach to replicate the mixing processes of the brine jets. Besides numerical simulations, a series of experiments using the planar laser-induced fluorescence technique is carried out to compare each numerical simulation with its experimental correspondence. Both numerical and experimental results are presented in comparative figures compared to previous experimental data. The comparisons indicated that the LES model could reasonably predict the geometrical and mixing characteristics of inclined dense jets; however, the flow features are still underestimated by up to 25%. Moreover, the model could reproduce the local concentration build-up near the impact point. The processes within the near-wall region leading to this local decrease of dilution are discussed in detail. Additionally, a novel criterion is proposed to predict when the flow reaches a quasi-steady-state. The criterion can be used to manage the computational expenses, especially in simulations with high demanding computing power such as LES.

倾斜的密集射流通常用于减轻沿海海水淡化厂盐水排放对环境的影响。已经进行了大量研究以数值模拟该过程中流动的复杂结构。然而，该过程的数值预测仍然是一个挑战。本文使用大涡模拟 (LES) 方法对角度为 15°、30°、45°、60° 和 75° 的倾斜密集射流进行了全面的数值研究，特别强调了近壁区域，其中最复杂的流动结构发生。目的是评估 LES 方法复制盐水喷射混合过程的能力。除了数值模拟，使用平面激光诱导荧光技术进行了一系列实验，以将每个数值模拟与其实验对应进行比较。与以前的实验数据相比，数值和实验结果都以比较图的形式呈现。对比表明，LES模型可以合理地预测倾斜密集射流的几何特征和混合特征；然而，流动特征仍然被低估了高达 25%。此外，该模型可以再现撞击点附近的局部浓度累积。详细讨论了导致这种局部稀释减少的近壁区域内的过程。此外，提出了一种新的标准来预测流动何时达到准稳态。该标准可用于管理计算费用，