Water flows through a two-dimensional diffuser having a \(20^{\circ}\) expansion angle as shown in Fig. P6.40. Assume that the flow in the diffuser can be treated as a radial flow emanating from a source at the origin \(O\).

(a) If the velocity at the entrance is \(20 \mathrm{~m} / \mathrm{s}\), determine an expression for the pressure gradient along the diffuser walls.

(b) What is the pressure rise between the entrance and exit?

Figure P6.40

0 Diffuser wall Entrance 7 m Flow 20 Exit