Before revision: The total drag and component drag forces can be related as follows: where: A is the planform area of the body, S is the wet surface of the body, is the pressure drag coefficient, is the friction drag coefficient, is the unit vector in the direction of the shear stress acting on the body surface dS, is the unit vector in the direction perpendicular to the body surface dS, pointing from the fluid to the solid, magnitude of the shear stress acting on the body surface dS, is the pressure far away from the body (note that this constant does not affect the final result), is pressure at surface dS, is the unit vector in direction of free stream flow Therefore, when the drag is dominated by a frictional component, the body is called a streamlined body; whereas in the case of dominant pressure drag, the body is called a blunt or bluff body.
After revision: The total drag and component drag forces can be related as follows: where: is the planform area of the body, is the wet surface of the body, is the pressure drag coefficient, is the friction drag coefficient, is the unit vector in the direction of the shear stress acting on the body surface dS, is the unit vector in the direction perpendicular to the body surface dS, pointing from the fluid to the solid, magnitude of the shear stress acting on the body surface dS, is the pressure far away from the body (note that this constant does not affect the final result), is pressure at surface dS, is the unit vector in direction of free stream flow Therefore, when the drag is dominated by a frictional component, the body is called a streamlined body; whereas in the case of dominant pressure drag, the body is called a blunt or bluff body.