Suppose a convergentdivergent nozzle is operated as case h i
     Suppose a convergent-divergent nozzle is operated as case h in Fig. 15.17 What kind of nozzle could have the same exit pressure, but with a reversible flow?  FIGURE 15.17  Nozzle pressure ratio as a function of back pressure for a convergent-divergent nozzle.   
  
  Solution
The nozzle that will have same exit pressure, but reversible flow, is a convergent nozzle having supersonic flow everywhere asssuming the pressure ratio greater than critical pressure.

