求教！

雨烟子

这是我要加入的源项的形式，但不知道如何加，一定要化成TC（V-Qp）吗？如何画？

moitoi

it is very simple, to read phoenics-book 200b ground and plant

雨烟子

我看了关于plant的说明，但还是不太明白，能不能说的清楚一点？谢谢！

phoenics

由于word软件的原因我没有办法看到你的公式，提供下面阻力源项的添加方法，希望能给你一些帮助。
Q1. Question: - How do I set resistance terms, such as the Ergun Equation?
Answer:
Introduction
The ERGUN equation represents the pressure drop associated with flow through a packed bed, or more generally, a porous medium.
In PHOENICS, pressure drops are applied as sinks in the momentum equation. The units of the momentum equation are those of force, so the pressure drop must also be turned into a force.
The ERGUN equation can be written as:
dp/dx = a*U1 + b*U12
where a=µ/K and b is an empirical constant. Here, µ is the dynamic viscosity of the fluid flowing through the porous media and K is an empirical constant called the permeability.
The pressure drop can be turned  into a force, as follows:
Fx = Area * dp
= Area * dp/dx * dx
Now Area = dy * dz;
so dx * Area = Volume
Hence:
Fx = Volume * (a*U1 + b*U12)
Implementation
The velocities used in the equation are superficial velocities, so
This can be introduced as two patches:
PATCH(ERGUN1, VOLUME, ........
COVAL(ERGUN1, U1, a, 0.0)
PATCH(ERGUN2, VOLUME, ........
COVAL(ERGUN2, U1, -b, 0.0)
Note that the -ve COefficient in patch ERGUN2 is activating a quadratic source - as stated in POLIS.
In the VR-Editor, the above can be achieved by giving an object the type User-Defined, and setting two patches with the Attributes as described above.

phoenics

我终于打开了你的word文件，你这不是源项的问题，你用你的方程和N-S方程对照，将相同的部分放在方程左面，不同的部分放在方程右面将来做源项处理。然后再加两个方程C和T。

雨烟子

谢谢phoenics！
  我就是想把这个不同的部分作为源项处理，这不同的部分写入phoenics需要用plant写入，是不是就要把这部分化成TC（V－Qp）这种形式，用patch和coval命令写入？相当于附加源项？请你给我详细说明一下？

phoenics

首先要将源项线性化，具体方法请找参考书。然后用PATCH，COVAL形式将源项写入。
是不是使用PLANT看你的具体情况。