Lagrangian chaos and heat transfer
HEAT TRANSFER 1998
6: GENERAL PAPERS
We present the experimental results of the effects of chaotic advection on heat transfer intensification. Experiments have been performed on shell-and-tube heat exchangers. Temperature efficiency of two heat exchangers, one with chaotic twisted-pipe coil and the other with helically coiled tube have been compared. It is shown that for the same initial and boundary conditions the chaotic heat exchanger results in an efficiency gain of up to 28% higher than that of helically coiled heat exchanger. The pressure drops are comparable for both configurations. A mathematical criterion "integral correlation dimension Dc" for degree of disorder is proposed for quantification of the efficiency of the above geometries for passive tracer dispersion. It is found that the theoretical value of Dc approaches its asymptotic value 2 for a quite reasonable number of bends (16) in a chaotic twisted pipe flow. It is shown that Dc agrees quite satisfactorily with the state of mixing in spatial advection obtained by particle trajectory tracking.