Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.
Louvered fin and round tube heat exchangers are widely
used in air conditioning devices and heat pumps. In this study
the effect of punching delta winglet vortex generators into the
louvered fin surface in the near wake region of each tube was
investigated. Numerical simulations were performed on the
compound design and the thermal and hydraulic characteristics
were evaluated. It was found that the delta winglets can
significantly reduce the size of the wake regions. This results in
an enhanced heat transfer. Further, it was shown that the
vortices do not propagate far downstream. Due to the flow
deflection they are destroyed in the downstream louver bank.
For the configuration studied, the pressure drop penalty of
adding vortex generators was also significant, indicating that an
optimization is necessary to select a compound design with
improved overall performance.