For part 2, check this link: https://youtu.be/kyHjWGnrByQ
In this video, we will go over the aerodynamic features of the Porsche Taycan and prepare it for road testing! Special thanks to the Porsche Centre in Mechelen, Belgium, for letting us play with this fantastic car 😊
In our last video, we had optimized the rear of the Porsche Taycan using our Aerodynamic Shape Optimization technique (to have it generate more downforce), In this video, we get up close with all the other special features of this car (underfloor, diffuser, wheels, …)
At the front splitter, the air jumps underneath the car and accelerates as it gets into the channel formed by the road surface and the underfloor of the car. This increased velocity will reduce the pressure, creating a suction force pulling the car downward (which is good for handling).
On electric cars, the underfloor can be made very smooth & flat, as it sits below the battery pack and as they have very little exposed components. So the air maintain its velocity and connect with the diffuser at the rear, where it connects to the wake behind the car, reducing drag, increasing downforce and so on.
Wheels are a major source of aerodynamic drag on cars. They are large, unshielded elements rotating through the air, acting like a mixer. Not only do they generate drag themselves, they also create turbulent air downstream, which can increase drag / reduce performance elsewhere.
Porsche has fitted the car with air curtains, which are channels in the front bumper. The opening at the front accepts the high pressure are at the nose of the car which is then sped up to exit at high velocity through a slot at the rear of the front bumper, just ahead of the front wheel. This creates a curtain, shielding the turbulent air coming off the rotating wheel.
Another feature are the aerodynamic rims. To limit their drag, they created a rim which is more “covered” than a regular rim. Secondly, the profile of the spokes has been designed in such a way that the air nicely slides across the spokes, instead of being pushed away by more blunt spoke shapes.
And finally, Porsche also air deflectors in front of the wheels: these are small “ramps” that divert the air so it doesn’t hit the wheels directly (where it would create a large wake). These are present both at the front & the rear wheels.
The active rear spoiler will automatically extend when you are going fast enough to improve downforce & aero balance of the car.
Air is forced through the coolers and this represents an energy loss. So when you don’t need full cooling power, it’s good for efficiency to (partially or fully) close the entrance to the coolers. This will reduce the energy lost on air going through the coolers and will make the air go around the car instead.
The Porsche Taycan has an extremely low drag coefficient of 0.22 and one of the tricks to achieve this is to lower the ride height of the car. Lowering the ride height at low speeds would be impractical towards ground clearance, speed bumps etc, so it is lowered dynamically as the car picks up speed. A lower ride height also has a positive impact on the handling of the car, as downforce typically increases with reduced ride height.
We equipped the car with tufts, which are small strands of wool that will align themselves with the local orientation of the airflow. This allows us to analyse flow patterns and see where the air has detached and/or has become turbulent.
Stay tuned for our next video, where we’ll take the car for a ride and compare the tuft patterns with what we saw in simulations!
The AirShaper videos cover the basics of aerodynamics (aerodynamic drag, drag & lift coefficients, boundary layer theory, flow separation, reynolds number...), simulation aspects (computational fluid dynamics, CFD meshing, ...) and aerodynamic testing (wind tunnel testing, flow visualization, ...).
We then use those basics to explain the aerodynamics of (race) cars (aerodynamic efficiency of electric vehicles, aerodynamic drag, downforce, aero maps, formula one aerodynamics, ...), drones and airplanes (propellers, airfoils, electric aviation, eVTOLS, ...), motorcycles (wind buffeting, motogp aerodynamics, ...) and more!
For more information, visit www.airshaper.com