Effect of void fraction covariance on two-fluid model based code calculation in pipe flow

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

4 Scopus Citations
View graph of relations

Author(s)

Detail(s)

Original languageEnglish
Pages (from-to)319-333
Journal / PublicationProgress in Nuclear Energy
Volume108
Online published20 Jun 2018
Publication statusPublished - Sept 2018
Externally publishedYes

Abstract

Utilization of one-dimensional system analysis code such as TRACE, RELAP5, TRAC-BF1 to evaluate gas-liquid two-phase flow behaviors in nuclear power plants is crucial for the plant-level safety assessment. In the two-fluid model, interfacial momentum transfer between two phases is expressed under interfacial drag term in the momentum equation. For the rigorous and accurate expression of interfacial drag term and drift flux parameter, covariance due to the area averaging of void fraction distribution must be considered. In the present paper, an effect of the covariance on void fraction prediction in pipe flow was numerically assessed by implementing Hibiki and Ozaki's model into the interfacial drag term in the one-dimensional two-fluid model. For the low flow rate with high void fraction conditions, it was found that the inclusion of covariance model slightly underestimated void fraction value than that calculated by the drift-flux model. This underestimation comes from the momentum source term in the two-fluid model, which was derived under the assumption of uniform void fraction distribution. Therefore, in this paper, momentum source term was rederived with consideration of void fraction covariance and a complete set of momentum equation and constitutive formulations for the one-dimensional two-fluid model is presented.

Research Area(s)

  • Covariance, Interfacial drag force, Momentum equation, Two-fluid model, Void fraction

Citation Format(s)

Effect of void fraction covariance on two-fluid model based code calculation in pipe flow. / Ozaki, Tetsuhiro; Hibiki, Takashi; Miwa, Shuichiro et al.
In: Progress in Nuclear Energy, Vol. 108, 09.2018, p. 319-333.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review