Chapter 12, Problem 1P

To determine

Stagnation pressure and how it is measured.

Explanation of Solution

Stagnation point and stagnation pressure:

When a stationary object is immersed in a fluid flow stream, the fluid is stopped at the nose (foremost part of object) of the object. This point is called as stagnation point. The pressure that is measured at the stagnation point is known as stagnation pressure. The stagnation pressure is equal to the sum of the static and dynamic pressure.

It is mathematically expressed as follows:

  $P_{\text{stag}}=P+\frac{\rho V^2}{2}$

Here, the static pressure is $P$, the density of the fluid is $\rho$, and the velocity of the fluid is $V$.

The stagnation pressure is measured by using the device called pitot tube.