# Setting Up a Simulation Using Porous Media

**URL:** https://www.simscale.com/forum/t/setting-up-a-simulation-using-porous-media/36293
**Category:** Project Support
**Created:** [August 4, 2016, 9:11pm UTC](https://www.simscale.com/forum/t/setting-up-a-simulation-using-porous-media/36293 "2016-08-04T21:11:44Z")
**Posts on this page:** 1
**Showing post:** 5

<div class="post-metadata">

### Author: ![ibrito](https://www.simscale.com/forum/letter_avatar/ibrito/32/5_5575768a8748004e209b776fc1b2916d.png) [@ibrito](https://www.simscale.com/forum/u/ibrito)
#### Post date: [August 10, 2016, 3:11pm UTC](https://www.simscale.com/forum/t/setting-up-a-simulation-using-porous-media/36293/5 "2016-08-10T15:11:43Z")

</div>

Hi everyone! Thank you for the attention, especially you @varsey!

However I still couldn’t get this simulation running. You explained the e1 and e3 vectors but I didn’t quite understand the diference between these vectors and the Darcy-Forchheimer’s.

> [@varsey](#):
>
> The second thing: e1, e2 are the principal directions, so your porous media will be aligned along this directions. For example, if you have a porous zone inclined of 45° with respect to the x direction of the reference frame in your mesh, you should replace e1 with something like (in 2D)

In my example I should set my Darcy-Forchheimer parameters’ vectors in a way that the ‘Y’ and ‘Z’ components are zero, right? It means that the porous media is only permissible in that direction (X). With that being said, what does these e1 and e3 vectors really represent? Once I determined the direction of the porous surface, what will theses e1 and e3 vectors change? I’m sorry but I couldn’t understand the physics behind it. That’s probably why I still can’t run this simulation without resulting in errors.

Thanks in advance for the attention!

---

_[View the full topic](https://www.simscale.com/forum/t/setting-up-a-simulation-using-porous-media/36293)._