An open-wheel car is a car with the wheels outside the car's main body, and usually having only one seat. Open-wheel cars contrast with street cars, sports cars, stock cars, and touring cars, which have their wheels below the body or inside fenders. Open-wheel cars are built both for road racing and oval track racing. Open-wheel cars licensed for use on public roads, such as the Ariel Atom, are uncommon, as they are often impractical for everyday use.
A tire is a ring-shaped component that surrounds a wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide traction on the surface over which the wheel travels. Most tires, such as those for automobiles and bicycles, are pneumatically inflated structures, providing a flexible cushion that absorbs shock as the tire rolls over rough features on the surface. Tires provide a footprint, called a contact patch, designed to match the vehicle's weight and the bearing on the surface that it rolls over by exerting a pressure that will avoid deforming the surface.
Automotive aerodynamics is the study of the aerodynamics of road vehicles. Its main goals are reducing drag and wind noise, minimizing noise emission, and preventing undesired lift forces and other causes of aerodynamic instability at high speeds. Air is also considered a fluid in this case. For some classes of racing vehicles, it may also be important to produce downforce to improve traction and thus cornering abilities.
Automobile handling and vehicle handling are descriptions of the way a wheeled vehicle responds and reacts to the inputs of a driver, as well as how it moves along a track or road. It is commonly judged by how a vehicle performs particularly during cornering, acceleration, and braking as well as on the vehicle's directional stability when moving in steady state condition.
A monster truck is a specialized off-road vehicle with a heavy duty suspension, four-wheel steering, large-displacement V8 engines and oversized tires constructed for competition and entertainment uses. Originally created by modifying stock pickup trucks and sport utility vehicles (SUVs), they have evolved into purpose-built vehicles with tube-frame chassis and fiberglass bodies rather than metal. A competition monster truck is typically 12 feet (3.7 m) tall, and equipped with 66-inch (1.7 m) off-road tires.
Aquaplaning or hydroplaning by the tires of a road vehicle, aircraft or other wheeled vehicle occurs when a layer of water builds between the wheels of the vehicle and the road surface, leading to a loss of traction that prevents the vehicle from responding to control inputs. If it occurs to all wheels simultaneously, the vehicle becomes, in effect, an uncontrolled sled. Aquaplaning is a different phenomenon from when water on the surface of the roadway merely acts as a lubricant. Traction is diminished on wet pavement even when aquaplaning is not occurring.
A flap is a high-lift device used to reduce the stalling speed of an aircraft wing at a given weight. Flaps are usually mounted on the wing trailing edges of a fixed-wing aircraft. Flaps are used to reduce the take-off distance and the landing distance. Flaps also cause an increase in drag so they are retracted when not needed.
Rolling resistance, sometimes called rolling friction or rolling drag, is the force resisting the motion when a body rolls on a surface. It is mainly caused by non-elastic effects; that is, not all the energy needed for deformation of the wheel, roadbed, etc., is recovered when the pressure is removed. Two forms of this are hysteresis losses, and permanent (plastic) deformation of the object or the surface. Note that the slippage between the wheel and the surface also results in energy dissipation. Although some researchers have included this term in rolling resistance, some suggest that this dissipation term should be treated separately from rolling resistance because it is due to the applied torque to the wheel and the resultant slip between the wheel and ground, which is called slip loss or slip resistance. In addition, only the so-called slip resistance involves friction, therefore the name "rolling friction" is to an extent a misnomer.
A spoiler is an automotive aerodynamic device whose intended design function is to 'spoil' unfavorable air movement across the body of a vehicle in motion, usually manifested as lift, turbulence, or drag. Spoilers on the front of a vehicle are often called air dams.
A glossary of terms relating to automotive design.
Fender skirts, known in Australia and the United Kingdom as spats or covers, are pieces of bodywork attached to or part of the fender that cover the upper portions of the wheels of a vehicle. They are usually used only on rear wheels, but some models have them on all wheels.
Fender is the American English term for the part of an automobile, motorcycle or other vehicle body that frames a wheel well. Its primary purpose is to prevent sand, mud, rocks, liquids, and other road spray from being thrown into the air by the rotating tire. Fenders are typically rigid and can be damaged by contact with the road surface.
A roof flap is an aerodynamic feature on race cars, mainly stock cars, which functions as an emergency spoiler to prevent the vehicle from lifting off the ground. The flaps are stowed during normal vehicle operation; however, in certain situations, e.g., if the vehicle goes into a spin, particularly if it is facing backwards, the flaps deploy to disrupt the air flow over the roof and reduce the lift force on the vehicle.
The drag coefficient is a common measure in automotive design as it pertains to aerodynamics. Drag is a force that acts parallel to and in the same direction as the airflow. The drag coefficient of an automobile measures the way the automobile passes through the surrounding air. When automobile companies design a new vehicle they take into consideration the automobile drag coefficient in addition to the other performance characteristics. Aerodynamic drag increases with the square of speed; therefore it becomes critically important at higher speeds. Reducing the drag coefficient in an automobile improves the performance of the vehicle as it pertains to speed and fuel efficiency. There are many different ways to reduce the drag of a vehicle. A common way to measure the drag of the vehicle is through the drag area.
A slat is an aerodynamic surface on the leading edge of the wing of a fixed-wing aircraft. When retracted, the slat lies flush with the rest of the wing. A slat is deployed by sliding forward, opening a slot between the wing and the slat. Air from below the slat flows through the slot and replaces the boundary layer that has travelled at high speed around the leading edge of the slat, losing a significant amount of its kinetic energy due to skin friction drag. When deployed, slats allow the wings to operate at a higher angle of attack before stalling. With slats deployed an aircraft can fly at slower speeds, allowing it to take off and land in shorter distances. They are used during takeoff and landing and while performing low-speed maneuvers which may take the aircraft close to a stall. Slats are retracted in normal flight to minimize drag.
The following is a glossary of terminology used in motorsport, along with explanations of their meanings.
Road debris, a form of road hazard, is debris on or off a road. Road debris includes substances, materials, and objects that are foreign to the normal roadway environment. Debris may be produced by vehicular or non-vehicular sources, but in all cases it is considered litter, a form of solid waste. Debris may tend to collect in areas where vehicles do not drive, such as on the edges (shoulder), around traffic islands, and junctions.
A mudflap is an accessory on wheel wells of a motor vehicle.
In automotive design, a nolder is a small aerodynamic shape integral to bodywork or to an aerodynamic attachment – e.g., a spoiler, diffuser or splitter – perpendicular to the direction of air flow travel for the purpose of further managing and refining air flow.
On a bicycle, a fender American English or mudguard British English is a part that encloses a tire so that it stops spray of water, sand, mud, stones and other road debris from thrown into the air by the rotating wheel. Full-covering fenders go over most of the upper side of the tire, and are considered standard equipment on utility bikes. Sports bikes can have smaller fenders or be completely fenderless, especially on bikes made for use in drier climates.
