Limitations in the Use of the Equivalent Diameter
Open Access
- 1 January 2016
- journal article
- research article
- Published by Scientific Research Publishing, Inc. in World Journal of Nuclear Science and Technology
- Vol. 06 (01), 53-62
- https://doi.org/10.4236/wjnst.2016.61005
Abstract
This paper deals with the inaccuracy assessment of the friction pressure loss estimation based on Darcy formula combined with an equivalent hydraulic diameter and a friction factor valid for circular pipes when applied to a square rod bundle. The assessment has been done by comparing the analytical and semi-empirical predictions with two different CFD codes results: CFX and NEPTUNE_CFD. Two different analytical approaches have been considered: the whole-bundle and sub-channel approaches, both for laminar and turbulent flow conditions. Looking at results, it is reasonable to assume that an error in the range of 11% - 23% is likely when using equivalent diameter in the laminar regime. In the case of turbulent regime, the equivalent diameter works better and the error is in the range between a few percent and ~12%.Keywords
This publication has 1 reference indexed in Scilit:
- The structure of turbulent flow in triangular array rod bundlesNuclear Engineering and Design, 1975