A water-tunnel test section has a 1-m diameter and flow properties V = 20 m/s, p =100

Question:

A water-tunnel test section has a 1-m diameter and flow properties V = 20 m/s, p =100 kPa, and T = 20°C. The boundary-layer blockage at the end of the section is 9 percent. If a conical diffuser is to be added at the end of the section to achieve maximum pressure recovery, what should its angle, length, exit diameter, and exit pressure be?