Details

Autor(en) / Beteiligte

• Qi, Hongyuan
• Liang, Aiguo
• Jiang, Huayi
• Shi, Jianying
• Sun, Nana
• Wang, Yulong

Titel

Surface wettability and flow properties of non-metallic pipes in laminar flow

Ist Teil von

• Chinese journal of chemical engineering, 2020-03, Vol.28 (3), p.636-642

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• In this paper, three liquids flowing in five pipes with the same inner diameter of 14 mm were studied to determine the relationship between the surface wettability and flow properties in laminar flow (Re < 2000). This was motivated by oilfield observations of increased pressure drops in non-metallic pipes compared to those in metal pipes, which was contrary to expectations. A new expression for the frictional coefficient that considers the Reynolds number and contact angle θ in laminar flow for non-metallic pipes was proposed based on the experimental results of single-phase flow using dimension and regression analyses. The solutions of the anomalous phenomenon were proposed from the perspectives of the pipe diameter, contact-angle difference, and the compatibility between flexible composite pipe and JLHW105 oil according to the new formula. The surprising finding was that the surface wettability could control the frictional resistance by the critical contact angle (39.9°) obtained at the same Reynolds number. If 0° < θ ≤ 39.9°, the frictional coefficient increased as the contact angle increased. In contrast, if 39.9° < θ < 180°, the frictional coefficient decreased with increasing contact angle. The influences of the pipe diameter and contact-angle difference on the pressure drop difference of JLHW105 oil showed an inversely proportional relation. A series of materials and liquids were tested. The selection of pipe material for transporting a given fluid can be based on the contact angle, surface tension, and critical limit of the contact angle obtained. The research results are expected to provide some guidelines for the selection of the appropriate pipe material for a given set of fluids.