Aerodynamic devices allowed a vehicle to take advantage of wind around it. Some devices, such as those feeding a radiator or engine, improve the efficiency of airflows within the vehicle’s body. Other gadgets boost traction by creating downforce.
Positive pressure intakes/scoops
Scoops, or positive pressure intakes, help give a combustion engine a modest “Ram Air” or “Supercharging” effect. They function on the idea that when a “air box” is subjected to a steady and approaching air flow, the air within compresses. The air box includes an aperture that allows enough air to flow in, and the expanding air box slows the air flow to increase the pressure inside the box. The higher the pressure and air volume via the air box, the faster the vehicle moves. A scoop and an air box are shown in the diagram AD1 below:
When air needs to be brought into a region that isn’t exposed to the scoop’s direct approaching air flow, NACA ducts come in handy. NACA ducts are frequently utilised along the sides of a vehicle. The NACA duct takes use of the Boundary layer, a slow-moving layer of air that “clings” to the car’s bodywork, particularly if the bodywork flattens or does not accelerate or decelerate the air flow. Good examples include the top and side body panels. The layer thickens as the roof or body panels get longer (a source of drag that grows as the layer thickens).
A specifically designed intake in the NACA duct scavenges this slower moving section. As illustrated in picture AD2, the intake form is angled inwards toward the interior of the bodywork, drawing slow-moving air into the NACA duct’s aperture. The “walls” of the duct design also produce vortices, which help in scavenging. The duct’s form and depth change are crucial for optimal operation.
Spoilers
Spoilers are commonly employed on sedan-type racing cars and road vehicles to give downforce and combat the natural inclination of these cars to become “light” in the rear owing to lift caused by the rear body form.
Spoilers operate as air flow barriers, allowing increased air pressure to build up in front of the spoiler. Downforce is created by the increased pressure acting on the trunk/deck region, and the flow is controlled to raise pressure in the diagram AD3.
Air Dam in the Front
The purpose of a front air dam is to keep air from flowing underneath a vehicle. This is accomplished by erecting a “dam” or wall across the front of the vehicle that reaches close to the road and, in certain cases, along the sides. As seen in diagram AD4 below, this generates a vacuum or low pressure space beneath the automobile. Downforce is generated at the front of the vehicle due to the low pressure region and the greater pressures over the front and top of the vehicle.
