Forced convective heat transfer from unconfined isothermal and isoflux elliptic cylinders

摘要

This article presents the numerical study of laminar forced convective heat transfer from elliptic cylinders of various axis ratios (AR=0.1, 0.4, 0.6, 0.8, and 1.0), angles of attack (AOA=30°, 45°, 60°, and 90°), and Reynolds numbers (Re=50, 100, 150, and 200). Simulations are carried out for both isothermal and isoflux wall boundary conditions. A detailed study of flow field reveals distinct instantaneous and time-averaged flow patterns behind the elliptic cylinder. The effect of flow patterns on isotherms and, thus, on heat transfer, is analyzed in detail. Local and surface averaged Nusselt number (Nu and Nu_(avg)) is computed and their variation due to change in AR, AOA, and Re is studied. It is observed that increasing AR and Re increases Nu _(avg) monotonically, while increasing AOA decreases Nu_(avg). Finally, correlations are proposed for Nu_(avg) with respect to AR, AOA, and Re with minimum rms error.