Effect of laminarization and retransition on heat transfer for low Reynolds number flow through a converging to constant area duct
Abstract
The process of reversion from the laminarized flow to turbulence is investigated by means of systematic experiments using the kkL model. A fully developed low Reynolds number turbulent air flow between two parallel plates with a spacing of 15 mm is laminarized through a linearly converging passage 200 mm in length. It then flows into a parallelplate channel again, resulting in a decrease in the Nusselt number, at first, in the downstream parallel plate section together with the friction coefficient. Reversion to turbulence proceeds gradually and manifests itself as a sharp increase in the Nusselt number and friction coefficient. Flow and heat transfer in the converging and parallel sections can be accurately predicted by the kkL model, provided that the extent of laminarization at the inlet of the parallel plate section is not very high.
 Publication:

ASME Journal of Heat Transfer
 Pub Date:
 May 1982
 Bibcode:
 1982ATJHT.104..363T
 Keywords:

 Ducted Flow;
 Heat Transfer Coefficients;
 Laminar Flow;
 Parallel Plates;
 Reynolds Number;
 Transition Flow;
 Turbulent Flow;
 Air Flow;
 Coefficient Of Friction;
 Convergence;
 Kinetic Energy;
 Nusselt Number;
 Fluid Mechanics and Heat Transfer