# Drag Coefficient result?
**URL:** https://www.simscale.com/forum/t/drag-coefficient-result/83404
**Category:** Project Support
**Created:** [November 3, 2018, 3:27pm UTC](https://www.simscale.com/forum/t/drag-coefficient-result/83404 "2018-11-03T15:27:34Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@bluematt2002](https://www.simscale.com/forum/u/bluematt2002)
#### Post date: [November 3, 2018, 3:27pm UTC](https://www.simscale.com/forum/t/drag-coefficient-result/83404/1 "2018-11-03T15:27:34Z")
Hi , I am trying to find the drag coefficient for a body, however when I set up a result control I get one value, but when I go into para view and do calculations though there I get another value.
I get a much lower drag coefficient in para view, then in the result control, so my question is how is Simscale calculating the drag coefficient?
In ParaView I use this equation for drag coefficient : Cd = D / (A \* .5 \* r \* V^2)
where D, drag is in newtons, A is reference in meters, r is density of fluid, and v is velocity of fluid.
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### Author:  [@jousefm](https://www.simscale.com/forum/u/jousefm)
#### Post date: [November 3, 2018, 3:40pm UTC](https://www.simscale.com/forum/t/drag-coefficient-result/83404/2 "2018-11-03T15:40:01Z")
Hi @bluematt2002!
These resources might be helpful for you:
- **[How to determine the coefficient drag in Paraview](https://www.simscale.com/forum/t/how-to-determine-the-coefficient-drag-in-paraview/64753)**
- **[Lift and drag coefficient calculation in simscale - #2 by jousefm](https://www.simscale.com/forum/t/lift-and-drag-coefficient-calculation-in-simscale/82167/2)**
- **[Lift/downforce calculation help - #10 by 1318980](https://www.simscale.com/forum/t/lift-downforce-calculation-help/46174/10)**
* * *
Also feel free to share your project with us so that we can see what setup you have chosen.
Cheers,
Jousef
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### Author:  [@1318980](https://www.simscale.com/forum/u/1318980)
#### Post date: [November 3, 2018, 3:44pm UTC](https://www.simscale.com/forum/t/drag-coefficient-result/83404/3 "2018-11-03T15:44:20Z")
@bluematt2002 I presume you are neglecting viscous forces in your paraview calculation? The platform takes this into account for drag coefficient.
You can add the wall shear stress as a result control and use it to calculate the drag component due to viscous forces. If this still produces different results, can you share your method of calculation in paraview?
Best,
Darren
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### Author:  [@bluematt2002](https://www.simscale.com/forum/u/bluematt2002)
#### Post date: [November 3, 2018, 3:51pm UTC](https://www.simscale.com/forum/t/drag-coefficient-result/83404/4 "2018-11-03T15:51:43Z")
yes I have wall shear stress as a result control, however I don’t know how to incorporate this into the equation.
My current set up is just calculating drag, then I find the drag coefficient by hand as that is a little faster.
in ParaView, to find drag I have: Normals\_z_p_-1
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### Author:  [@1318980](https://www.simscale.com/forum/u/1318980)
#### Post date: [November 3, 2018, 4:03pm UTC](https://www.simscale.com/forum/t/drag-coefficient-result/83404/5 "2018-11-03T16:03:35Z")
So for pressure forces you probably do surface normals times pressure. Then integrated respect to area will give forces in x, y and z. For viscous wall shear stress is just force/area so you can do wall shear integrated respect to area, giving the viscous forces in cuz, where the z components in your case should give the total drag force to use in your hand calculations.
Best,
Darren
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### Author:  [@bluematt2002](https://www.simscale.com/forum/u/bluematt2002)
#### Post date: [November 3, 2018, 4:06pm UTC](https://www.simscale.com/forum/t/drag-coefficient-result/83404/6 "2018-11-03T16:06:28Z")
what do you mean by integrated? how do I integrate with the calculator filter?
Integrate Variables?
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### Author:  [@1318980](https://www.simscale.com/forum/u/1318980)
#### Post date: [November 3, 2018, 4:14pm UTC](https://www.simscale.com/forum/t/drag-coefficient-result/83404/7 "2018-11-03T16:14:37Z")
Hi @bluematt2002, yes integrate variables.
Best,
Darren
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### Author:  [@bluematt2002](https://www.simscale.com/forum/u/bluematt2002)
#### Post date: [November 3, 2018, 5:17pm UTC](https://www.simscale.com/forum/t/drag-coefficient-result/83404/8 "2018-11-03T17:17:50Z")
When I integrate the wallshearstress\_z, is the result given in Pa?
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### Author:  [@1318980](https://www.simscale.com/forum/u/1318980)
#### Post date: [November 3, 2018, 5:25pm UTC](https://www.simscale.com/forum/t/drag-coefficient-result/83404/9 "2018-11-03T17:25:54Z")
The theory is that tau=f/a integrated f/a.da=f therefore Newton’s.
Best,
Darren
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### Author:  [@JPzanca](https://www.simscale.com/forum/u/JPzanca)
#### Post date: [March 24, 2020, 7:27pm UTC](https://www.simscale.com/forum/t/drag-coefficient-result/83404/10 "2020-03-24T19:27:58Z")
Hey, i have the same problem! My results of Lift and Drag are different on Paraview. What do you made to solve that? I don’t know which one i chose
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### Author:  [@Ricardopg](https://www.simscale.com/forum/u/Ricardopg)
#### Post date: [March 25, 2020, 12:44am UTC](https://www.simscale.com/forum/t/drag-coefficient-result/83404/11 "2020-03-25T00:44:00Z")
Hey @JPzanca,
Have a look at this [thread](https://www.simscale.com/forum/t/retsam-pandora-box-dale-continuation-simulation-project-by-dalekramer/86409). Best approach is to rotate the directions for Cd and Cl based on AoA (assuming you’re dealing with airfoils).
For reference (sorry for my bad paint skills 🙄)
