Fundamentals
When a fluid flows over the surface of a body, pressure is exerted on the body. This pressure multiplied by the surface area results into a force, since pressure is defined as this resultant force is a vector quantity with both magnitude and direction. The component of this total force that is perpendicular to the direction of flow of the fluid is called the lift. The other component of this force that is parallel to the direction of flow of the fluid is called the drag. If the lift force is positive, the object is able to fly but if negative, the object ...
