  Fluidic transport in inverted T-shaped cavities with the flow entering
through the top and exiting from the two bottom outlets experiences an
interesting phenomenon that causes particles having density lower than that of
the fluid medium to get trapped at the junction, in a horizontal formation.
However, this only occurs across a small range of Reynolds numbers and that too
in the laminar regime. The unexpected phenomenon is conjectured to be modulated
by formation of vortex tubes in the flow. Interestingly enough, such T-shaped
(or, more generically, Y-shaped) cavities are also seen quite widely in
anatomic pathways, e.g., in animal upper airways. It can be hypothesized that
this trapping phenomenon can emerge in such geometries as well. Our current
model simulates the occurrence with water as the ambient fluid medium passing
through an idealized T-shaped space and measures the length of the vortices in
each of the arms of the junction. In our study, we have conducted the
investigation using a Reynolds number of 400 that lies in the laminar regime
and have estimated the vortex tube lengths using the concept of nodal maximum
velocities that the streamwise flow would attain on vortex dissipation.
Vorticity and helicity contour variations as one goes further away from the
junction have also been reported.
