The Effect of Bubbles on a Car’s Fuel Efficiency

Abstract

Since the first automobile in 1885, researchers have been constantly improving the aerodynamics of cars. Aerodynamics plays a huge part in reducing fuel efficiency of cars, as reducing the drag of the car will benefit its efficiency. Approaches like more streamlined models, diffusers, and front splitters, have been used throughout automotive history in an attempt to improve cars’ aerodynamics. Recently, golf ball-like bubbles have been placed on a racing-focused supercar to reduce the drag and lift of said car through reducing the separation point on the car, decreasing the size of the vacuum behind the car. This concept could potentially be used to increase the fuel efficiency of the average production car, reducing fuel consumption and emissions. Placement of bubbles along the trunk and roof of an average sedan are tested and compared with a control car. Bubbles along the trunk provided a 2.39% decrease in drag and a 1.6% increase in the fuel economy of the average production sedan, while bubbles along the roof only increased the drag coefficient and decreased the fuel efficiency of the sedan. In conclusion, bubbles provide very slim benefits and require more research and development before they become viable enough to use on production automobiles. The purpose of this research paper is to explore this method of increasing fuel efficiency.