GM is Experimenting With Plasma Aerodynamics

Plasma is perhaps the most misunderstood of the four fundamental states of matter on earth.

Unlike the Earth’s other three states–solid, liquid, and gas–we don’t really interact with plasma in most normal situations. In fact, plasma is only generated by subjecting a neutral gas to an electromagnetic field to the point that it becomes ionized. However, the process isn’t as radical as it might sound, for example, the Northern Lights are believed to be a form of plasma, while neon lights get their glow from a mild form of ionization. Sailors and pilots are familiar with the phenomenon as the legendary St.Elmo’s fire.

Since the collapse of the Soviet Union, plasma has been investigated as the next big thing in the field of aerodynamics. It started with the heavy hitters in aerospace before the commercial trucking industry got wind of its drag reducing promise. Now, documents published by the United States Patent and Trademark Office reveal that General Motors has picked up the thread as a possible solution for meeting perpetually rising fuel economy standards.

Plasma aerodynamics effectively operate using the same principles that are baked into ionized air purifiers, but with a twist. Surface electrodes emitted by actuators force the surrounding air to become energized which causes the component molecules to break down into ions and electrons which then become plasma “clouds”. Those clouds can then be directed and used to shape surface airflow without the need for moving parts.

According to the document, GM is looking at plasma aerodynamics in order to control the “flow separation” of turbulent air as it comes off the back of a moving vehicle. Of course, they could just shape the car into a smooth phallic shape that would slide through the air with supreme ease, but the company acknowledges that such a drastic measure would severely impact the car’s aesthetics and desirability among consumers.

The attached drawings show the strategic placement of plasma actuators on the A-pillars, which would begin shaping the air as it travels towards more actuators located above the rear window, on top of the rear deck, and at the edges of the rear fascia. Air would also be controlled under the car with actuators working to keep air from getting tossed up into the wheels or from escaping along the flanks, before helping it accelerate from the rear.

GM says the actuators themselves “could be configured as a small strip, similar in thickness to a strip of aluminum foil.” The thickness of the strip would have the potential to be increased in order to create a stronger acting plasma cloud, through the use of increased voltages.

For now, the technology is only really being investigated as a fuel saver, but there is language within the document that points to a far more exciting future for the technology. For instance, GM claims that through the use of plasma it can influence airflow in a matter of mere milliseconds, which is blindingly fast compared to the hydraulically actuated systems in place on performance cars like the Ford GT and McLaren 720S.

Aerospace engineers have long considered how plasma could be deployed to help airplane wings create more lift with less drag–imagine if you took those lessons on lift, and inverted them, instead, using the technology to generate downforce without the speed sucking drag that normally comes as consequence.