The ratio of the drag on a body moving through air to the product of the velocity and the surface area of the body. A sleek car has a drag coefficient, or "Cd", of about 0.30; a square, flat plate's is 1.98. Also signified by Cx.
A dimensionless measure of the aerodynamic sleekness of an object.
A dimensionless number used in calculating the aerodynamic drag acting on a car. The drag coefficient is a function of such factors as the shape of a car and airflow through the car for cooling or ventilation.
Measure of calculating aerodynamic drag (wind resistance), being a function of shape.
A coefficient representing the drag on a given airfoil or other body, or a coefficient representing a particular element of drag. Used to describe the amount of resistance created by a moving vehicles bodywork and aerodynamic aids designed to create downforce or smooth out the flow of air. The lower the number, the better.
A dimensionless value that allows the comparison of drag incurred by different sized and different shaped bodies.
A measure of a vehicle's efficiency as an aerodynamic shape, useful for comparison with other vehicle designs. It is a mathematical factor that, when multiplied by the projected square footage area of the vehicle, gives its drag force in pounds. C d is derived by measuring the drag force and dividing it by the product of dynamic pressure and vehicle frontal area. Drag coefficient (C d ) = force/dynamic pressure x frontal area; the lower the C d number, the better the aerodynamic efficiency
Normalized drag force, makes the comparison of the aerodynamic properties of different sized objects possible; Definition.
A measure of the aerodynamic sleekness of an object. Drag coefficient is signified by "dc.: The lower the number, the greater the aerodynamic efficiency. The higher the drag coefficient, the more a car's engine must work to keep a given road speed. Also known as "CD" for coefficient of drag."
See Coefficient Of Drag (CD).
A term used for coefficient of drag.
A dimensionless ratio of the component of force parallel to the direction of flow ( drag) exerted on a body by a fluid to the kinetic energy of the fluid multiplied by a characteristic surface area of the body. In symbols, the drag coefficient is where is the fluid density, the speed, and characteristic length of the body. Rayleigh's formula expresses the drag coefficient as proportional to a power of the Reynolds number (Re), For Couette flow, = −1 and the constant is 2. In most aerodynamic experiments lies between −1/4 and −1/2. The drag coefficient for the force exerted by the atmosphere on the earth is called the skin-friction coefficient.
The drag coefficient (Cd, Cx or Cw, depending on the country) is a dimensionless quantity that describes a characteristic amount of aerodynamic drag caused by fluid flow, used in the drag equation. Two objects of the same frontal area moving at the same speed through a fluid will experience a drag force proportional to their Cd numbers. Coefficients for rough unstreamlined objects can be 1 or more, for smooth object much less.