Closed-form analytical jump
conditions
across normal shock waves in pure vapour-droplet flows have been
derived
for different boundary conditions. They are equally applicable to
partly
and fully dispersed shock waves. Collectively they may be called the
generalized
Rankine-Hugoniot relations for wet vapour. A phase diagram is
constructed
which specifies the type of shock structure obtained in vapour-droplet
flow given some overall parameters. It is shown that in addition to the
partly and fully dispersed shock waves that are possible in any
relaxing
medium, there also exists a class of shock waves in wet vapour in which
the two-phase relaxing medium reverts to a single-phase non-relaxing
one.
An analytical expression for the limiting upstream wetness fraction
below
which complete evaporation will take place inside a shock of specified
strength has been deduced. A new theory has been formulated which shows
that, depending on the upstream wetness fraction, a continuous
transition
exists for the shock velocity between its frozen and fully equilibrium
values. The mechanisms of entropy production inside a shock are also
discussed.
