Assessment of Various Low-Reynolds Number Turbulence Models for Friction and Heat Transfer in Smooth and Rough Pipes

• Main Authors: Kuan-Ju,Chiu, 邱冠儒
• Other Authors: Yi-Lung,Yang
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/45208337519702428681

碩士 === 中華大學 === 機械工程學系碩士班 === 100 === Five versions of low Reynolds number turbulent models for the prediction of heat transfer under a fully developed turbulent pipe were analyzed by comparison with the experimental data. None of the low Reynolds number turbulent models are capable of predicting the local Nusselt number in good agreement with experimental results beyond Reynolds number 106. The error in Nusselt number at low and high Prandtl numbers is more pronounced than the Prandtl number at 1. Regardless the poor performance of various low Reynolds number models in fully developed turbulent pipe problems, the Launder and Sharma model was used to study the transient length, constant wall or constant heat flux, and wavy wall in a two-dimensional configuration. Several conclusions were drawn based on the current study.