Aerodynamic Drag

In aerodynamics, aerodynamic drag is the fluid drag force that acts on any moving solid body in the direction of the fluid freestream flow. From the body's perspective (near-field approach), the drag comes from forces due to pressure distributions over the body surface, symbolized, and forces due to skin friction, which is a result of viscosity, denoted . Alternatively, calculated from the flowfield perspective (far-field approach), the drag force comes from three natural phenomena: shock waves, vortex sheet, and viscosity.