We have a full simulation running at present and will be further analysing the results once we have some more solid data! From a balance perspective, taking into account that cooling flow will vary this, this first pass seems a little forward biased, but we’ll see what the detailed results show. Large vortices form off the sides of the front window and run up the A-Pillar and over to the upper surface of the truck bed cover where they unwrap and circulate in the opposite direction, helping to entrain more flow down behind the vehicle and stabilise the wake, whilst reducing the adverse pressure gradient on the rear surface which is what helps to reduce that separation effect. However, despite the small region of separation, the long gentle sloping rear tray cover allows for the flow to reattach and the teardrop shape helps to minimise the wake of the vehicle and reduce drag compared to a typical truck body. This isn’t as big as we’d normally expect as we are running at 100kph which is much lower than our typical race car work. this sets up clean flow for the wake region.Īcross the top of the truck, you have a favorable pressure gradient on the windscreen that leads to the peak in the roofline which trips the flow and causes a region of separation or recirculating flow (read: drag) across the centre section of the truck. The flow through the underbody is quite good, as the ride height is quite high and we assumed it has a smooth underbody. Without details of a cooling system, this is probably exaggerated in this simulation as the cooling will help to bleed some flow through the front and reduce the separation. Starting at the front, the squared off shape disrupts the airflow considerably but it recovers part way along the bonnet due to the oncoming flow (favorable pressure gradient). ![]() 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.From these quick results, we can see the following flow features. The next image shows turbulent energy isosurfaces. 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. Wherever there is turbulence generated, there will be drag. This first animation shows the general “wind tunnel” with the turbulent energy shown trailing each truck. This is simulated in SOLIDWORKS Flow Simulation as a sort of “virtual wind tunnel” but with additional inputs for ground movement and tire rotation. ![]() We set up all the vehicles to run side-by-side at typical expressway speeds of 70mph. Note: Silverado frontal area slightly smaller than other vehicles. Streamlined model on far left and simple box on the far right.įigure 6 – Same frontal areas. In this case a streamlined teardrop design and a simple rectangular box.įigure 5 – The competitors. This file took a lot of work to clean-up and special thanks to my colleague Arun for working late to take this on.įinally, we introduced two other “vehicles” to measure the extremes. Left to right: closed bed, open bed, no fairingsįor comparison, we downloaded a CAD model of a competitor product (Chevy Silverado) from an online database. One with an open bed, and another without the side fairings which, strangely, actually looks like a truck (don’t mind the glass). 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.įrom this model, we introduced other variations of the Cybertruck. 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.įigure 2 – Cybertruck SOLIDWORKS CAD Construction Our model didn’t come directly from Tesla. ![]() ![]() It’s important to understand the CAD model to understand the assumptions involved in our Cybertruck simulation. Modeling the Cybertruck and other variations in CAD Let’s explore the aerodynamic performance of the Cybertruck with SOLIDWORKS Flow Simulation and let the results speak for themselves. 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. News of Tesla’s Cybertruck was released on Friday, November 22 nd and the internet was divided. Figure 1 – Transient Animation of Cybertruck Flow Development
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