Gambit 多孔介质.docx

Porous Media ConditionsThe porous media model can be used for a wide variety of problems, including flows through packed beds, filter papers, perforated plates, flow distributors, and tube banks. When you use this model, you define a cell zone in which the porous media model is applied and the pressure loss in the flow is determined via your inputs as described in Section? 7.19.2. Heat transfer through the medium can also be represented, subject to the assumption of thermal equilibrium between the medium and the fluid flow, as described in Section? 7.19.3. 多孔介质可以用于许多广泛的问题，包括填充层过滤纸,穿孔平板,流量分配器,管排等。当你使用这个模型时，你定义一个cell zone来使用多孔介质模型，并且流动中的压力损失通过你输入决定。通过多孔介质传热同样可以描述，给予在多孔介质和流体流动之间的热平衡假设。A 1D simplification of the porous media model, termed the porous jump, can be used to model a thin membrane with known velocity/pressure-drop characteristics. The porous jump model is applied to a face zone, not to a cell zone, and should be used (instead of the full porous media model) whenever possible because it is more robust and yields better convergence. See Section? 7.22 for details. 多孔介质的一维简化称之为“porous jump”，可以用来在知道速度/压降特征的情况下模拟很薄的隔膜。porous jump模型适用于face zone，而不是cell zone，并且尽可能的使用（代替完整的多孔介质模型）因为它更耐用，显示出更好的收敛性。Limitations and Assumptions of the Porous Media ModelThe porous media model incorporates an empirically determined flow resistance in a region of your model defined as porous. In essence, the porous media model is nothing more than an added momentum sink in the governing momentum equations. As such, the following modeling assumptions and limitations should be readily recognized: 在你定义为多孔的区域，多孔介质模型结合一个决定经验的流动阻力。本质上，多孔介质模型只不过是在动量方程里附加了一个动量汇，如此的，接下来的模型假设和局限性显而易见。Since the volume blockage that is physically present is not represented in the model, by default FLUENT uses and reports a superficial velocity inside the porous medium, based on the volumetric flow rate, to ensure continuity of the velocity vectors across the porous medium interface. As a more accurate alternative, you c