Numerical investigation of developing convective heat transfer in a rotating helical pipe

Numerical simulation is carried out for heat transfer characteristics of flow in rotating helical pipes. A good agreement has been achieved compared with experimental data from literature. The impacts of both co-rotation and counter rotation on local heat transfer enhancement are discussed in detail. Different developing modes of heat transfer enhancement in laminar and transitional regions are observed. Streamwise variation of circumferential distribution of heat transfer enhancement by rotation exhibits sensitivity to rotation speed, rotation direction and curvature ratio. Within the range of De and Ro under discussion, the impact of streamwise inertial force is the major factor of heat transfer enhancement for co-rotational cases while the effect of reversed flow and accompanied Dean vortex for counter rotational cases cannot be neglected. (C) 2014 Elsevier Ltd. All rights reserved.