CFD of Tesla Cybertruck

SalmonMan · December 2, 2019, 09:13

Hi.

I've done a CFD analysis of Tesla Cybertruck using Simscale(cloud based openFoam).

Full blog: https://englogs.com/2019/11/30/cfd-a...la-cybertruck/

The Cd (Coefficient of drag) is 0.387.

Simulation: https://www.simscale.com/projects/Sa..._cybertruck-4/

Let me know what you think.

Taichi

JBeilke · December 3, 2019, 07:16

I also did an aerodynamic calculation of another phantasie product -- Anakin Skywalkers podracer :-)

flotus1 · December 3, 2019, 07:47

Is your podracer going backwards?

JBeilke · December 3, 2019, 08:29

Hmmm. It looks like this. Maybe I tried to minimize the drag and found, that it works much better in this direction.

I think that is was just a test of the Harpoon mesher more than 15 years ago :-)

kandelabr · December 11, 2019, 05:03

I too made the simulation and got different results.
https://damogranlabs.com/2019/12/tes...-aerodynamics/

SalmonMan · December 11, 2019, 05:22

Interesting. Thank you for sharing it!

Which CAD model did you use? Which one on GrabCAD?

Someone needs to do an experiment to see the actual flow then

Quote:

Originally Posted by kandelabr

I too made the simulation and got different results.
https://damogranlabs.com/2019/12/tes...-aerodynamics/

kandelabr · December 11, 2019, 06:39

I think it was this one: https://grabcad.com/library/tesla-cy...k-3d-printed-1

Don't expect measurements to be very different (like 0.3 or whatever)

SalmonMan · December 11, 2019, 07:41

Are you sure?
My CAD software says it's only about 16inch wide though. So the Reynolds number is definitely different... then I realised you mentioned the model had been scaled up in your blog

The model I've made is a simplified one and it could well be over-simplified. I may try making a more detailed one in the future.

Quote:

Originally Posted by kandelabr

I think it was this one: https://grabcad.com/library/tesla-cy...k-3d-printed-1

Don't expect measurements to be very different (like 0.3 or whatever)

kandelabr · December 11, 2019, 09:28

I guess this is the fatal difference. You can't just scale the model - you need to keep the same Reynolds number. That's why wind tunnels are often heated (up to 200°C!) to lower viscosity for scaled models.

SalmonMan · December 11, 2019, 09:36

I know and I didn't scale up or anything mate.
I made the model based on the actual dimensions although it's not 100% accurate obviously.

You said, in your blog, that you had scaled up the model size in CAD software to match the real size, didn't you?

Quote:

Originally Posted by kandelabr

I guess this is the fatal difference. You can't just scale the model - you need to keep the same Reynolds number. That's why wind tunnels are often heated (up to 200°C!) to lower viscosity for scaled models.

kandelabr · December 11, 2019, 10:05

Yes, I did. I have no idea which units it was made in anyway. I also wrote it's not a very precise model, when scaled up to specified length width and height didn't match.

December 2, 2019, 09:13	CFD of Tesla Cybertruck	#1
SalmonMan New Member Taichi Yoshida Join Date: Dec 2019 Posts: 5 Rep Power: 7	Hi. I've done a CFD analysis of Tesla Cybertruck using Simscale(cloud based openFoam). Full blog: https://englogs.com/2019/11/30/cfd-a...la-cybertruck/ The Cd (Coefficient of drag) is 0.387. Simulation: https://www.simscale.com/projects/Sa..._cybertruck-4/ Let me know what you think. Taichi fresty, BlnPhoenix and CGarcia like this.

December 3, 2019, 07:47		#3
flotus1 Super Moderator Alex Join Date: Jun 2012 Location: Germany Posts: 3,427 Rep Power: 49	Is your podracer going backwards? sbaffini and SalmonMan like this.

December 3, 2019, 08:29		#4
JBeilke Senior Member Joern Beilke Join Date: Mar 2009 Location: Dresden Posts: 539 Rep Power: 20	Hmmm. It looks like this. Maybe I tried to minimize the drag and found, that it works much better in this direction. I think that is was just a test of the Harpoon mesher more than 15 years ago :-) SalmonMan likes this.

December 11, 2019, 05:03		#5
kandelabr Senior Member Nejc Join Date: Feb 2017 Location: Slovenia Posts: 196 Rep Power: 9	I too made the simulation and got different results. https://damogranlabs.com/2019/12/tes...-aerodynamics/ sbaffini likes this. __________________ www.damogranlabs.com

December 11, 2019, 06:39		#7
kandelabr Senior Member Nejc Join Date: Feb 2017 Location: Slovenia Posts: 196 Rep Power: 9	I think it was this one: https://grabcad.com/library/tesla-cy...k-3d-printed-1 Don't expect measurements to be very different (like 0.3 or whatever) __________________ www.damogranlabs.com

December 11, 2019, 09:28		#9
kandelabr Senior Member Nejc Join Date: Feb 2017 Location: Slovenia Posts: 196 Rep Power: 9	I guess this is the fatal difference. You can't just scale the model - you need to keep the same Reynolds number. That's why wind tunnels are often heated (up to 200°C!) to lower viscosity for scaled models. __________________ www.damogranlabs.com

December 11, 2019, 10:05		#11
kandelabr Senior Member Nejc Join Date: Feb 2017 Location: Slovenia Posts: 196 Rep Power: 9	Yes, I did. I have no idea which units it was made in anyway. I also wrote it's not a very precise model, when scaled up to specified length width and height didn't match. __________________ www.damogranlabs.com

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