Spoiler (cars)

The spoiler should not be confused with a wing , the main task of which is to increase the downforce of the car, thereby increasing the adhesion properties of the latter with the supporting surface ^[1] . Wings usually increase the aerodynamic drag of a car.

By location on the body

• Skirts bumpers.
• Side skirts side skirts .
• Roof Spoilers roof spoilers .
• The rear spoiler is installed at the rear end of the car, on the trunk lid (or the hood of the rear-engine cars). The design of such a spoiler is sometimes used not only for aerodynamic effect, but also for hardening the trunk lid ^[2] .

By Style

In the American and global tuning industry, there are two styles of spoilers:

• Factory style English. OEM style - most often in this style spoilers are made no different from products manufactured by the manufacturers of the automobiles themselves.
• Individual style English. custom style - individual spoilers are made in small batches and have a variety of forms, sometimes these are products tested in the wind tunnel, and sometimes an absolutely irrational tribute to fashion, although manufacturers often point out the perfect aerodynamic qualities of spoilers.

By function

Dirt-resistant spoilers are used, for example, to prevent "suction" from under the bottom of the flow of air carrying dirt from the road to the rear window. Such spoilers create and direct the cutting air flow from above. The drag coefficient varies slightly.

Spoilers are made from:

• Fiberglass (fiberglass). Fiber-reinforced plastic based on synthetic resins. The use of this material in the manufacture of automobile parts is primarily dictated by the low cost of manufacture. Fiberglass spoiler consists of a fiberglass filler bonded with synthetic resin. Fiberglass is quite strong and can be processed well, but in massive quantities the manufacture becomes unprofitable.

• ABS plastic. The bulk of the factory car spoilers are made by casting from ABS plastic with various impurities, giving this light but rather fragile material plasticity. The weakness of this material is its fragility, which increases with age of the product (due to the evaporation of volatile phenols). Inexpensive to manufacture.

• Silicones. Since recent times, organosilicon polymers (silicones) have been used in production. The advantage of this material is its great ductility. Silicones have high thermal performance and a long service life.

• Carbon fiber ( carbon ). The most modern material is an analogue of fiberglass based on carbon fiber, ( carbon fiber ). Carbon fiber (carbon) is a lightweight, sturdy and very expensive material. Unlike ordinary fiberglass, the hardening of the binder resin occurs in a pressure chamber at high pressure and temperature. In this regard, the labor and energy intensity in the manufacture does not allow mass manufacturers to widely use this material in the automotive industry.
• Steel and aluminum. As a rule, the “blade” of the spoiler is made of aluminum strip, and the struts and flaps are made of sheet steel.

The principle of operation depends on the type of spoiler ^[3] :

• The rear spoiler located on the boot lid increases air pressure above the boot lid and the rear window. Without a spoiler, a rarefaction of air is formed in this place, which reduces the downforce (negative pressure lifts the car) and increases the resistance (negative pressure creates a force directed backward). The rear spoiler increases air pressure over the rear of the car and thereby improves downforce (up to 15% when measured on a Volkswagen Scirocco ) and resistance (up to 5%). In addition, there is an unexpected ^[4] decrease in air pressure under the car, which also improves downforce. The effect of decreasing resistance disappears with increasing spoiler height ^[4] , but such spoilers are sometimes used to increase downforce.
• The skirt on the front bumper ( English front spoiler ) deflects the main air flow from the bottom of the car. Such a spoiler introduces additional resistance by increasing the cross section of the car, but it reduces the resistance to liquid friction created by the interaction of the air flow with the bottom of the car; this friction is very significant because of the inevitably protruding into the flow under the bottom of the suspension and transmission parts. The front spoiler also leads to a decrease in pressure under the front of the car, which leads both to an increase in downforce and, in the front position of the engine, to an improvement in the circulation of air cooling the engine ^[5] .

In motorsport, a “spoiler” is a concept that denotes an aerodynamic plane that is fastened with its front end to the upper edge of the rear of the race car and at an angle to the air flow. The purpose of the spoiler is to create a vacuum behind the car, which accelerates the movement of air masses under the bottom, thereby reducing the air pressure in this place and creating downforce. Spoilers used in motorsport, as a rule, have the ability to adjust, so that you can achieve changes in certain characteristics, depending on the race track.

• Wing
• Diffuser (car)

• Wolf-Heinrich Hucho. Aerodynamics of Road Vehicles: From Fluid Mechanics to Vehicle Engineering . - Elsevier, 2013 .-- S. 167-175. - 576 p. (eng.)
• Simon McBeath. Airdams, Splitters and Spoilers // Competition Car Aerodynamics . - Veloce Publishing Ltd, 2017 .-- 320 p. (eng.)