Escuela Politécnica Superior, University of Zaragoza, 22071 Huesca, Spain.
Department of Agri-Food Engineering and Biotechnology, Universitat Politécnica de Catalunya, Castelldefels, 08860 Barcelona, Spain.
Molecules. 2020 Apr 18;25(8):1870. doi: 10.3390/molecules25081870.
Agitation inside agricultural sprayer tanks can be studied while using an international standard procedure, based on obtaining internal samples of liquid. However, in practice, this test is not easy to perform. Herein, we propose the explicit study of the mixing procedure with biphasic computer simulations using Computational Fluid Dynamics (CFD). An experimental test was performed on a 3000 L tank of a commercial air-assisted sprayer, with two different agitation system configurations, in order to compare the results of several theoretical physical models of biphasic flows for CFD, both Eulerian and Lagrangian. From the analysis of these theoretical models, we conclude that the Volume of Fluid model is not viable and the Discrete Phase Model produces erroneous results, while the Eulerian and Mixture models can both be useful. However, the results obtained suggest that complex streams generated by real-world agitation systems produce more errors in calculations. Both models can be conducted in the design phase, prior to the implementation of the machine. In addition, the computer simulations allow for researchers to analyse the mixing process in detail, making it possible to evaluate the efficiency of an agitation system according to the time that is required to reach mixture homogeneity.
可以使用基于获取液体内部样本的国际标准程序来研究农用喷雾器罐内的搅动情况。然而，在实际中，这项测试不易执行。在此，我们提出使用计算流体动力学（CFD）对两相计算机模拟进行混合过程的明确研究。在商业空气辅助喷雾器的 3000 升罐上进行了一项实验测试，采用了两种不同的搅拌系统配置，以便比较 CFD 中几种两相流的理论物理模型的结果，包括欧拉和拉格朗日模型。通过对这些理论模型的分析，我们得出结论，即多相流模型不可行，离散相模型产生错误结果，而欧拉和混合物模型都可能有用。然而，结果表明，由真实世界搅拌系统产生的复杂流体会导致计算中的更多错误。这两种模型都可以在机器实施之前的设计阶段进行。此外，计算机模拟允许研究人员详细分析混合过程，根据达到混合物均匀性所需的时间来评估搅拌系统的效率。
