Consider a converging$-$diverging nozzle whose ratio of exit areas and

throat is equal to $6.$ During an experiment, the pressure and temperature of the reservoir

are kept constant and equal to $1$ MPa and $500$ K$,$ respectively, while the ambient pressure is

varied. Suppose that the experiment is carried out in a steady state and that the gas used is the

helium $($ $=1\mathrm{.}67$; R $=2078\mathrm{.}5$ J$/$kgK; cp $=5180\mathrm{.}7$ J$/$kgK$).$ Characterize the flow $($informing: the

Mach number at exit; the position of the shock is normal, if this occurs; presence of presence

oblique shocks or expansion waves; the type of flow $-$ completely subsonic,

blocked, partially supersonic; and the rate of entropy generation, if applicable$)$ for the

following static pressures at the outlet: $995$ kPa; $900$ kPa; $500$kPa; $100$ kPa; $5$kPa.