Fluid Forces

In Fluid Mechanics we consider forces upon fluid elements. It is necessary to discuss the type of forces that could act on fluid elements. These Forces could be divided into two categories - Surface Forces, $F_S$ and Body Forces, $F_B$ .

Figure 2.1 : Classification of forces

 

Surface forces are brought about by contact of fluid with another fluid or a solid body. The best example of this is pressure. The surface forces depend upon surface area of contact and do not depend upon the volume of fluid. On the other hand, body forces depend upon the volume of the substance and are distributed through the fluid element. Examples are weight of any substance, electromagnetic forces etc.

(c) Aerospace, Mechanical & Mechatronic Engg. 2005
University of Sydney