Convective heat transfer predictions in an axisymmetric jet impinging onto a flat plate using an improved k–ω model

摘要

The paper discusses the convective heat transfer prediction in turbulent axisymmetric jets impinging onto a flat plate using the k–ωmodel of Wilcox (2006) [14]. Improvements to the heat transfer predictions are obtained in flow regions characterized by large level of strain using an impingement invariant proposed by Manceau (2003) [19]. The Manceau term is carefully introduced in order to leave the k–ωmodel predictions unmodified for reference flows. This is obtained using a blending function of Menter (1994) [12]. As an alternative, a modification based on the von Karman length scale is also discussed. Both modifications do not lead to stability problems in flow regions characterized by large levels of strain, preserving the robustness of the k–ωmodel. Improvements have been obtained for convective heat transfer prediction in stagnation flow regions of axisymmetric jets impinging onto a flat plate with nozzle-plate distances H/D=2,6,10 and Reynolds numbers Re=23000,70000.