Tesla Patent Describes Underbody Fans To Increase Downforce, Reduce Dr

Tesla Patent Describes Underbody Fans To Increase Downforce, Reduce Drag

Ahead of Tesla’s now delayed Roadster event, Tesla has been granted a patent for a fan-driven system that increases downforce while reducing aerodynamic drag. The patent describes using battery-powered fans to control airflow beneath the vehicle, with expected gains in cornering grip and braking stability.

How the System Works

Tesla patent diagram of underbody airflow system

The design pulls air through an inlet on the underside, channels it through a duct, and discharges it from an outlet at the rear. By accelerating airflow under the floor, the system lowers pressure beneath the car to increase road adhesion.

The outlet at the rear is larger than the inlet, forming a diffuser that lets air expand and slow before it mixes with the surrounding flow behind the vehicle. According to the patent, this layout is intended to raise downforce while also cutting drag.

A diagram in the filing shows four electric fans arranged side by side, separated by vertical fins, or strakes, to guide the airflow.

Controlling Downforce at Low Speeds

Tesla patent airflow illustration with fans and diffuser

Passive aerodynamic aids rely on the air movement created by vehicle speed. Tesla’s proposed fan system would generate downforce regardless of speed, making it useful in slower corners as well as at higher speeds.

The system would likely engage automatically, similar to active spoilers, when certain conditions are met, such as a speed threshold.

Ways to Increase Downforce

The added downforce is aimed at providing more cornering grip and greater stability at high speeds, along with improved braking. Tesla filed the application on January 17, 2024, following a provisional filing on January 17, 2023.

The Roadster could benefit from the additional downforce described in the patent, especially with the optional gas thrusters. Tesla’s event was delayed to October 15th. A separate patent also describes an active wing for the Roadster, similar to the wing seen on the Model S Plaid during early testing.