Abstract:
This thesis deals with the numerical study of swirling turbulent
flow through an abrupt expansion, which has many practical
applications. The computer program used for this analysis
utilizes the k-€ model. The governing equations are discretized
over the appropriate control volumes using the hybrid
differencing scheme and nonuniform staggered grid.
The capability of the model in predicting such complex flows
having swirl and recirculation is tested by comparing with
available experimental data. It is shown that the model can
predict complex flows like swirling turbulent jet with sudden
expansion with reasonable accuracy. The effect of inlet
condition, type of swirl generation, swirl intensity, Reynolds
number and expansion ratio on the flow field are also examined.
It is observed that, change in inlet velocity profiles and method
of swirl generation at inlet has significant effect on the
distribution of fluid flow properties after expansion. Due to
moderate swirl on-axis recirculation is produced and due to high
swirl off-axis recirculation is produced in addition to the
corner recirculation produced by the sudden expansion geometry.
By proper nondimensionalization, we can plot profiles from which
the required flow variables can be interpreted at different swirl
levels and Reynolds number.
