  In this endeavor, the transients persisting in a vacuum ejector system (put
reference of my old paper) is studied by numerically simulating the flow field,
and experimentally validating the simulated results. An inertial effect was
discovered in the study due to which the direction of mass flux changes. As a
result of this, the recirculation zone moves forward and backward during the
transients and the pressure in the secondary chamber rises and falls. The
system behaves as a damped oscillatory flow in which the direction of mass flux
keeps on changing and finally settles down to a state where there is no mass
flux in either direction. The movement of recirculation zone due to this
inertial effect is studied in more detail for various flow and geometric
parameters. The results obtained show that the pressure and mass flux through
the secondary chamber depend highly on both the thickness of the primary and
secondary jet and the chamber volume. The inertial effect reduces with the
reduction in thickness of primary and secondary flow. The inertial effect is
found to be decreasing with increasing secondary chamber volume. It is also
found that, the inertial effect decreases as the primary jet pressure
increases, for all other parameters remaining the same. The computationally
simulated flow field and the pressure on the secondary chamber are compared
with the experimental data and found to be matching fairly well.
