Pressure Coefficient

In general, pressure is a dimensional quantity. Many a times, it is expressed in a non-dimensional form with respect to free stream flow and the ‘pressure coefficient' is defined as follows;

(3.7.5)

Here, are the free stream density and free stream velocity, respectively. The term is called as dynamic pressure. For incompressible flow, if a body is immersed in the free stream, then Bernoulli's equation can be written at any arbitrary point in the flow field as,

(3.7.6)

On the surface of the cylinder shown in Fig. 3.7.1, the velocity distribution can be obtained from Eq. (3.7.2) i.e.

(3.7.7)

 

Fig. 3.7.2: Maximum velocity in the flow over a circular cylinder.