Experimental Study on Single-Phase Liquid Friction Factor in Rolling Horizontal Pipe

Friction pressure drop of single-phase liquid in rolling tube with inner diameter 34.5mm was investigated to develop a general correction of friction factor.The test section was horizontally settled on the rolling platform,which was driven by link gearing and rotated around a set axis.Friction factor is obtained by applying for the energy equation and the Darcy formula.Comparing the experimental results between the rolling and stable state,it is found that the frictional pressure drop depended on not only the flow velocity,tube diameter,but also the rolling period,rolling angle and etc.It is also found that the rolling friction factor displayed the periodic change.By defining rolling Reynolds number and applying dimensional analysis,a new correction of single-phase friction factor is provided incorporating the effects of rolling parameters.The proposed correction can well predict the experimental data.