Basic equations

In Chapter 5 basic fluid mechanical equations are derived step by step. First, the continuity equation is deduced with the help of a ballon which passes through a constriction. Second, Cauchy’s equation of motion is set up with the stresses acting on a fluid volume which is described once more with a balloon that moves upon application of stress and gravity. The constitutive equation which describes the properties of the fluid considered is elaborated also from the scratch. With the above mentioned steps, it is easy to reach to the Euler and Navier-Stokes equations from which the Bernoulli and the momentum equation are derived.