Cybertruck Simulation: Deal or Dud?

by Shaun Bentley

Transient Animation of Cybertruck Flow Development
Figure 1 – Transient Animation of Cybertruck Flow Development

News of Tesla’s Cybertruck was released on Friday, November 22nd and the internet was divided.  Through all the buzz we wanted to help people make up their mind on whether or not this truck is a deal or a dud.  Let’s explore the aerodynamic performance of the Cybertruck with SOLIDWORKS Flow Simulation and let the results speak for themselves.

 

Modeling the Cybertruck and other variations in CAD

It’s important to understand the CAD model to understand the assumptions involved in our Cybertruck simulation.  Our model didn’t come directly from Tesla.  Through the use of dimensions provided in Tesla’s release presentation and some frontal and profile photos/renderings on the internet, we constructed a 3D model of Tesla’s Cybertruck.

 

Cybertruck SOLIDWORKS CAD Construction
Figure 2 – Cybertruck SOLIDWORKS CAD Construction

There were plenty of images available on the internet, so we were able to compare important facets of our reproduction to Tesla’s original to try to model the aerodynamically relevant features.

From this model, we introduced other variations of the Cybertruck.  One with an open bed, and another without the side fairings which, strangely, actually looks like a truck (don’t mind the glass) .

 

Cybertruck variations: closed bed, open bed, no fairings
Figure 3 – Cybertruck variations. Left to right: closed bed, open bed, no fairings

For comparison, we downloaded a CAD model of a competitor product (Chevy Silverado) from an online database.  This file took a lot of work to clean-up and special thanks to my colleague Arun for working late to take this on.

 

CAD Model Chevy Silverado
Figure 4 – Chevy Silverado

Finally, we introduced two other “vehicles” to measure the extremes.  In this case a streamlined teardrop design and a simple rectangular box.

 

Cybertruck Simulation: the competitors.
Figure 5 – The competitors.  Streamlined model on far left and simple box on the far right.

 

Comparison models: frontal areas.
Figure 6 – Same frontal areas. Note: Silverado frontal area slightly smaller than other vehicles.

 

Cybertruck FLOW Simulation results

We set up all the vehicles to run side-by-side at typical expressway speeds of 70mph.  This is simulated in SOLIDWORKS Flow Simulation as a sort of “virtual wind tunnel” but with additional inputs for ground movement and tire rotation.  Here were some of the relevant results.

 

Turbulence

This first animation shows the general “wind tunnel” with the turbulent energy shown trailing each truck.  Wherever there is turbulence generated, there will be drag.  Energy lost due to turbulence will cause average pressure acting on the rear surfaces to be much lower than the forward surfaces, leading to a net force acting against the vehicle’s motion.

 

Cybertruck Simulation - Flow Field animation
Figure 7 – Flow Field animation

The next image shows turbulent energy isosurfaces.  You can see the largest amount of turbulence on the box body and the smallest amount on the streamline body, but it’s difficult to make-out the precise difference between the truck models.

SOLIDWORKS Flow Simulation on the Cybertruck

 

Cybertruck Simulation: Turbulent Energy Isosurfaces
Figure 8 – Turbulent Energy Isosurfaces

Here’s a closer look at the Cybertruck open bed compared to the Silverado.  Which one do you think generates more turbulent energy?

 

Cybertruck vs. Silverado Simulation
Figure 9 – Open Bed vs. Silverado

 

Pressure Profiles

If we compare the pressures acting on the front and rear surfaces, we can see the differential in the average colors should give us the overall drag.  You can see, for example, the streamlined body (on the right) has some relatively low pressures on its front projection and higher pressures on its back projection compared to the other vehicles.

 

Cybertruck Simulation: Frontal and rear pressure projections
Figure 10 – Frontal and rear pressure projections. Left to right: Block, Chevy, no fairings, open bed, closed bed, streamlined

 

Drag Results

From here, the software does the
rest of the work to calculate the overall drag force, and here were the
results:

 

Drag Force Results
Figure 11 – Drag Force Results

I almost couldn’t believe the prismatic Cybertruck even without its side fairings would show better drag results than the old Silverado.

 

Get more information about SOLIDWORKS Flow Simulation

SOLIDWORKS Flow Simulation is a CFD software designed for the everyday SOLIDWORKS user and analyst.  Talk to a GoEngineer sales representative to learn more about professional versions, get pricing, and understand how it can impact your business. Let’s Talk

SOLIDWORKS Flow Simulation on the Cybertruck

12 thoughts on “Cybertruck Simulation: Deal or Dud?

  1. AvatarMichael Gardner

    While I’m hoping the laws change and allow us to have vehicles without sideview mirrors and instead opt for cameras by the time cybertruck releases, it would be nice to see a simulation with the required sideview mirrors.

    Reply
  2. AvatarGarrison

    Great comparison! One key issue though – not sure it’s fair to include side mirrors on the Silverado. I’d be interested to see how much that affects the calculations

    Reply
  3. AvatarNafnlaus

    Consider doing a sim with it dragging a trailer. I’m betting that the flow will detach at the peak of the truck in such a situation and flow straight over the trailer, instead of sticking to the tonneau.

    Reply
  4. AvatarEvan

    Very well done. Only one little problem. Should add side mirrors for Cybertruck, since it’s quite red in Silverado’s case.

    Reply
  5. AvatarMichele Connolly

    Ok, I am going to show my ignorance, but when I look at the Silverado vs the Tesla various options. it appears there is drag (red) around the side view mirrors and i don’t see side view mirrors on the Tesla. aren’t those needed by law? I don’t think it would change the end results, especially the enclosed Tesla option or maybe the Avalanche like Tesla option, but it seems like it may change the results of the traditional Tesla pick up truck.

    Reply
  6. AvatarFlowJoe

    Since the bodies are of different size, it would be better to compare Cd instead of just the drag force, and best yet the CdA. Then you can also compare them to many other car designs listed on Wikipedia here: https://en.wikipedia.org/wiki/Automobile_drag_coefficient
    I briefly summarize how to calculate the frontal area, A, with SOLIDWORKS in a blog post about Olympic bobsleds here: https://blogs.solidworks.com/solidworksblog/2014/04/can-cfd-tools-explain-the-aerodynamics-of-a-medal-winning-bobsled.html
    Where it reads: “Because the frontal area, used in the Cd calculation, is much more difficult to determine than for the sphere or disk models, I used the power of SOLIDWORKS 3D CAD to find this out. Since the model is an assembly file, I first saved it out as a single part; and the reason for doing this was so that I could export the model as a DXF file in the correct frontal orientation. SOLIDWORKS then allows me to open the DXF file that I created into a sketch in a new part. Now all I had to do was clean up the lines inside the exterior boundaries and then I could extrude the sketch to measure the area of the front face (see image below).”

    Reply
      1. AvatarFlowJoe

        Thank you, Shaun, for talking about the Defeature tool in SOLIDWORKS that appears that it will be the same thing but much more quickly. I’ll have to update my knowledge on this tool. Thanks!

        Reply

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