Note that, Bernoulli’s equation cannot be applied between sections 2 and 3 because the flow is unsteady. Now, and also . Therefore adding the last two equations gives: uu2 3 pp14 pressure of undisturbed fluid 22 32 4 1 1 2 pp u u . Combining this with the momentum equation gives: 14 2 2 uu u .
The MKS (meter-kilogram-second) units of the mass flow rate are kilograms per second, or kg/s. The mass flow rate has the same value at every point in a fluid conduit that has a single entry and single exit point. The mass flow rate at any two points along the conduit can be related like this, with the equation of continuity: About the Book Author