Research on the Flow Characteristics of Sudden-Reduction Oil Tube

Zhibin Zhang*, 1, Chunxi Lin1, Weiqiang Ye, An Wei1, Leming Xiao1, Wanzheng Ai2
1 Guangzhou Maritime Institute, Guangzhou 510725, China
2 Zhejiang Ocean University, Zhoushan 316021, China

© 2015 Zhang et al

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: ( This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Guangzhou Maritime Institute, Hongshan San Road, Huangpu, Guangzhoux, Postcard: 510725, China; Tel: 18922772102; E-mail:


The backflow region length in sudden-reduction oil tube is not only closely associated with its energy loss, but is also closely related to the partition between orifice plate and plug. In this paper, the characteristics of backflow region length in sudden-reduction oil tube are researched. The results illustrated that backflow region length decreases with the increase in the contraction ratio. Moreover, when Reynolds number is more than 105, Reynolds number has little impact on backflow region length. Empirical expression about backflow region length in sudden-reduction oil tube is also discussed in this paper.

Keywords: Backflow region, Contraction ratio, Reynolds number, Simulations, Sudden-reduction..