Turbulent fluid flow, heat transfer and onset of nucleate boiling in annular finned passages

An analytical model has been formulated for fully-developed turbulent flow and heat transfer in finned annuli using a modified mixing-length turbulenc e model. The model accounts for the conjugate heat transfer in the fluid an d the solid, and the finite thickness of the fins. Solutions were obtained using the finite element method adopting a mesh that exactly fits the solut ion domain with fine elements near the solid boundaries. Predictions of the model have been compared with experimental results For smooth and finned a nnuli with generally good agreement between data and predictions. The model has been extended to predict the conditions at the onset of nucleate boili ng using the criterion of Davis and Anderson. Again, these predictions agre ed well in magnitude and trend with experimental data of finned annuli. (C) 2000 Editions scientifiques et medicales Elsevier SAS.