We decided to increase fuel injection velocity at 20 m/s from previous
results at 5m/s : we take a restart file at 50000 iterations i.e t=22 ms.

We note that the flow has lost a part of his symmetry on the following
picture. However, the cross sections
show quite symmetrical profiles, and also falls in fuel mass fraction near
the wall behind the injector at x=0.1. We can make the same commentary
as the previous case about recirculation areas.

Moreover, we note that there are fuel rich areas which are coming undone
from the fuel jet. In fact, these areas traduce the existence of vortex.
Those vortices are traduced by an increasing of U velocity on the corresponding
shaded
contours. Those contours also show recirculation areas behind fuel
jet, where velocity is negative.

On the bottom left corner ( in front of the fuel jet), we can see a
fuel rich area which are coming undone from the fuel jet with negative
velocity ( it moves to the entry direction). This phenomenon is certainly
due to numerical diffusion. If we don't see the see thing on the top, it's
because the grid is not symmetrical.

The mean fuel mass fraction have been ploted after the last solution
(at 44 ms i.e. 100000 iterations) during 30000

iterations. We can conclude the same remarks than the instantaneous
fuel mass fraction contours : the flow is not

symmetrical, the outlet flow is not mixed. Particulary, the instantaneous
cross section at x=0.21 (outlet) is the same as the mean outlet cross section
of fuel mass fraction.

As the previous case, fuel flow rate is not enough important because
fuel and air are not mixed in the exit.

See animation for the corresponding case

Shaded contours of fuel mass fraction at t=35 ms

return to the commentary

Sections of fuel mass fraction
in x=0.1 (middle of the injector) and x=0.21 (outlet of the injector)

return to the commentary

Shaded contours ofU velocity (in x direction) at t=35 ms

return to the commentary

Mean shaded contours of fuel mass fraction

Mean outlet cross section of fuel mass fraction