Drag coefficient is a dimensionless number that depends on the projection area, fluid resistance and velocity. It is commonly denoted as Cd in aerodynamics calculations. Drag coefficient is used to quantify the drag or resistance of an object in a fluid environment, such as air or water.
Drag Coefficient depends on particular surface area, velocity of the fluid and resistance of fluid.
Drag coefficient is the unitless number obtained by dividing 2 times drag force by the square of the density velocity and the area.
Drag coefficient of a fluid depends on Drag force, that is the force component in the direction of the flow velocity, mass density of the fluid, flow speed of the object relative to the fluid and reference area.
The aerodynamic drag coefficient is a measure of the effectiveness of a streamline aerodynamic body shape in reducing the air resistance to the forward motion of a vehicle.
The drag coefficient is a function of several parameters like shape of the body, Reynolds Number for the flow, Froude number, Mach Number and roughness of the surface.