On the weak-equilibrium condition for derivation of algebraic heat flux model

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• 作者：J.-F. Qiu ; S. Obi ; T.B. Gatski
• 关键词：AHFM ; Weak-equilibrium condition ; Euclidean invariant ; Diffusive-transport constraint ; Evaluation
• 刊名：International Journal of Heat and Fluid Flow
• 出版年：2008
• 出版时间：December 2008
• 年：2008
• 卷：29
• 期：6
• 页码：1628-1637
• 全文大小：314 K

文摘

Analogous to an algebraic Reynolds stress model, the algebraic heat flux model (AHFM) is derived from a second-moment closure by invoking the weak-equilibrium condition. The present study investigates this condition in detail as it applies to the advection and diffusive-transport terms. For the advection term, the correct form of this condition in non-inertial frames is obtained by means of an invariant Euclidean transformation. The validity of the diffusive-transport condition is examined through an a priori test using a DNS database for rotating turbulent channel flow with heat transfer. It is shown that the weak-equilibrium condition applied to diffusive-transport term tends to fail in the near-wall region. An alternative form is proposed that is based on an asymptotic analysis of the transport equation budget in the near-wall region. An evaluation of proposed form shows that it has the potential to improve the predictive ability of an ARSM for flows involving system rotation and/or streamline curvature.