Abstract
• Comparatively studied thermal hydraulic characteristics of natural circulation loop under various motion conditions. • Obtained the periodic average frictional resistance coefficient and Nu. • Obtained the empirical relation of frictional resistance coefficient in turbulent region. • Under large flow rate conditions, rolling motion affects heat transfer characteristics mainly by affecting flow rate. • Some suggestions on the layout of marine natural circulation loop were given. In this present paper, an experimental research was carried out to investigate the influence of various motion conditions on the flow and heat transfer characteristics in natural circulation loops. A natural circulation loop was built on the six-degree-of-freedom motion experiment platform at Xi’an Jiaotong University (XJTU). First, it was found that the small acceleration heaving would not cause significant changes on flow rate of the natural circulation loop. Then, the influence mechanism of rolling motion on the natural circulation loop is different as the central axis of rolling is changed. The increase of additional inertial force along the coolant flow direction causes larger flow fluctuation. The periodic average frictional resistance coefficient under different working conditions is obtained, which is divided into flow fluctuation region ( Re < 5000) and turbulence region (5000 < Re < 35000). Last, according to the experimental data, a mathematical model to predict the periodic average frictional resistance coefficient which is suitable for the turbulent region is obtained, and the deviation between the predicted value and the experimental data is less than 20%. Beyond that, the period average Nu under different working conditions is also achieved. It shows that the rolling motion promotes the heat transfer with the small flow rate, while the rolling motion affects the heat transfer characteristics mainly by affecting the flow rate under the large flow rate conditions. Based on our research, some suggestions on the layout of marine natural circulation loop were given.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
