REFERENCE

Aerodynamics
Glossary

33 key terms from the world of motorsport aerodynamics, explained in plain language.

Aerodynamics

The study of how air moves around solid objects and the forces — lift, downforce, and drag — it creates as a result.

Angle of Attack

The angle between an airfoil's chord line and the direction of the oncoming airflow. A larger angle generally increases downforce, up to the point of stall.

Boundary Layer

The thin layer of air immediately adjacent to a surface. Speed ranges from zero right at the surface to the full freestream value a short distance away. Its behaviour — laminar or turbulent — strongly influences drag and separation.

Camber

The curvature of an airfoil's mean line relative to the chord. Higher camber increases downforce potential but also increases drag. A symmetrical airfoil has zero camber.

Centre of Pressure (CoP)

The single point through which the total aerodynamic resultant force can be imagined to act. Moving the CoP forward biases the car toward understeer; moving it rearward biases toward oversteer.

Chord

The straight-line distance from the leading edge to the trailing edge of an airfoil. It is the reference length against which thickness, camber, and other ratios are measured.

Diffuser

A gradually widening duct at the rear underside of a race car. Its job is to decelerate fast underfloor air smoothly and recover its pressure, sustaining the low-pressure zone under the car.

Downforce

A vertical aerodynamic force directed toward the track surface. It increases tyre normal load and therefore the grip available for cornering, braking, and acceleration.

Drag

The aerodynamic resistance force opposing forward motion. It has two main components: pressure (form) drag from the wake and skin-friction drag from air rubbing along surfaces.

Drag Coefficient (C_d)

A dimensionless number summarising how streamlined a shape is, independent of speed, density, or size. A lower C_d means less drag for a given frontal area and conditions.

DRS (Drag Reduction System)

A movable rear wing flap in Formula 1 that opens on designated straights, reducing the wing's angle of attack, cutting drag and gaining significant top speed.

Dynamic Pressure

The pressure associated with a fluid's motion, equal to ½ × density × speed². This is the quantity that drives all aerodynamic forces — double the speed and dynamic pressure quadruples.

Flow Separation

The point at which the boundary layer detaches from a surface. A low-pressure, recirculating wake forms downstream, significantly increasing pressure drag.

Form Drag

See Pressure Drag.

Ground Effect

Enhanced downforce produced by the underfloor of a race car as it squeezes airflow between the car body and the track, exploiting the Venturi effect to create a large low-pressure zone.

Gurney Flap

A small vertical tab at the trailing edge of a wing, typically 1–2% of chord in height. It creates a separation bubble that effectively increases circulation, gaining downforce for a modest drag penalty.

Induced Drag

Drag that is a byproduct of generating lift or downforce. It arises from the vortices shed at the wing tips as the pressure tries to equalise from the high-pressure side to the low-pressure side.

Laminar Flow

Smooth, orderly airflow where layers slide past each other without mixing. Laminar flow has lower skin friction than turbulent flow, but is more prone to separation under adverse pressure gradients.

Lift

An aerodynamic force perpendicular to the direction of airflow. On aircraft wings it acts upward; on race car wings it is inverted to act downward (downforce).

Outwash

The intentional sideways deflection of airflow by a front wing's outer sections, steering it around the front tyres to keep the floor inlets and downstream surfaces supplied with cleaner air.

Porpoising

A rapid oscillation in which downforce pulls the car down until underfloor flow stalls, downforce collapses, the car rises, flow reattaches, downforce returns, and the cycle repeats.

Pressure

The force per unit area exerted by air molecules on a surface. Differences in pressure across a surface are the fundamental mechanism behind lift, downforce, and drag.

Pressure Drag

Drag caused by the pressure imbalance between the high-pressure stagnation at the front of an object and the low-pressure separated wake at the rear. Also called form drag.

Ride Height

The gap between the underside of the car and the track surface. In ground-effect cars, ride height critically affects the underfloor Venturi geometry and therefore downforce.

Sidepod

The aerodynamic bodywork on the sides of a race car that houses the radiators and cooling ducts. Sidepod shape is a major aerodynamic design variable — especially its inlet size and undercut.

Skin-Friction Drag

Drag caused by viscous shear stress as air moves along the surface of an object. Every wetted surface contributes. Smooth, tightly fitted bodywork minimises this component.

Stall

A sudden loss of downforce (or lift) that occurs when an airfoil's angle of attack exceeds a critical value and the flow separates from the upper surface, destroying the pressure distribution.

Strakes

Small vertical fins mounted on the diffuser or floor edges to manage airflow laterally, prevent cross-flow, and help maintain the integrity of the diffuser's pressure recovery.

Turbulent Flow

Chaotic, mixing airflow with rapid fluctuations in velocity and direction. It has higher skin-friction drag than laminar flow but is more resistant to separation.

Venturi Effect

The pressure drop that occurs when a fluid is forced through a narrowing passage. The fluid speeds up to conserve mass flow, and by Bernoulli's principle its static pressure drops.

Vortex

A rotating column or tube of air. Engineers deliberately generate vortices — for example from cascade tips on front wings — to act as rotating seals that direct airflow precisely where it is needed.

Wake

The disturbed, low-energy, often turbulent region of air left behind a moving object. A large wake indicates a large pressure-drag penalty. Cars following closely in a wake experience reduced downforce (dirty air).

Wing Loading

The amount of downforce a wing generates. Higher wing loading means more cornering grip but also more induced and pressure drag.