Why Don't Car Makers Dimple Sheet Metal to Reduce Drag?

[Your name here]

This is my first post on this site and I figured I would maybe get a good answer to this question. If the dimples on a golf ball are to reduce the amount of friction due to air resistance, why don't car manufacturers dimple the sheet metal on their cars to reduce coefficient drag?? Just wondering.

 

[FredGarvin]

I believe Lexus is now doing it to the underside of one of it's vehicles. Since the vehicle is not spinning, I would think there would not be a need to dimple the entire surface of the vehicle, just where the aspect of a negative pressure gradient would want to cause separation of the BL (the rear side of the car). The dimpling would not be a good idea on the entire car for a couple of reasons I can think of:

1) Manufacturability would decrease i.e. it would be harder to make them.
2) The asthetics of the vehicle would be horrendous. The vehicle has to loog good or it won't sell.

 

[charng]

Thank you for your question. I can provide some insight into why car makers do not dimple sheet metal to reduce drag.

Firstly, it is important to understand that the dimples on a golf ball are designed to reduce drag by creating a turbulent boundary layer of air around the ball, which reduces the wake behind the ball and allows it to travel further. This works because the golf ball is a small, smooth object moving through a fluid (air). In contrast, cars are large, complex objects with many components and surfaces that interact with the surrounding air in different ways.

Secondly, dimpling sheet metal on a car would not have the same effect as on a golf ball. The dimples on a golf ball are specifically designed and strategically placed to create the desired turbulent boundary layer. In contrast, dimpling sheet metal on a car would create an uneven surface that could actually increase drag and reduce the overall aerodynamic efficiency of the vehicle.

Additionally, car manufacturers already use various techniques to reduce drag, such as designing sleek and streamlined body shapes, using spoilers and diffusers to manipulate airflow, and incorporating aerodynamic features like air dams and underbody panels. These methods are more effective and efficient than dimpling sheet metal.

Furthermore, dimpling sheet metal on cars could also have negative impacts on safety and structural integrity. The dimples could weaken the structural integrity of the metal, making it more susceptible to damage in the event of a collision. It could also create air pockets that could potentially affect the stability and handling of the vehicle.

In summary, while dimples may be effective for reducing drag on golf balls, they are not suitable for use on cars due to their size, complexity, and potential negative impacts on safety and performance. Car manufacturers use other methods to improve aerodynamics and reduce drag, which have been extensively tested and proven to be more effective. I hope this helps to answer your question.