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 k-kL 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 parallel-plate 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 k-kL 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