B314 再分配と壁面漸近挙動を考慮した非線形 2 方程式モデルによる乱流解析

概要

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Non-linear k-ε models have been extensively used in engineering applications. The existing non-linear models. however, can not satisfy the wall limiting behaviour of Reynolds stress component, <u^2_2>^^^- in the wall-normal direction, which is proportional to x^4_2 near the wall. Since the wall limiting behaviour of Reynolds stress diagonal components in the non-linear model is determined by the turbulence energy k, which is the highest order term in the model, the Reynolds stress components, <u^2_1>^^^-, <u^2_2>^^^- and <u^2_3>^^^- are proportional to x^2_2. In this study, we propose a new non-linear k-ε model which satisfies exactly the wall limiting behaviour of Reynolds stress components. The proposed model can also predict well the anisotropy in the normal stress components near the wall. Moreover, we reconstract the set of k-ε model including the proposed Reynolds stress expression. The reformed model is tested in channel flows with or without rotation and boundary layer flows with or without pressure gradients.
2001-07-31