(a) Consider a stream of fluid of density p with speed v₁, passing abruptly from a cylindrical pipe of cross-sectional area a₁ into a wider cylindrical pipe of cross-sectional area a₂ (see Fig. 16-37). The jet will mix with the surrounding fluid and, after the mixing, will flow on

almost uniformly with an average speed v2. Without referring to the details of the mixing use momentum ideas to show that the increase in pressure due to the mixing is approximately

(b) Show from Bernoulli’s equation that in a gradually widening pipe we would get

(c) Find the loss of pressure due to the abrupt enlargement of the pipe. Can you draw an analogy with elastic and inelastic collisions in particle mechanics?

Radhika Batra , 9 Years ago

Grade 11