CFD Modelling for flow and heat transfer in a closed Thermosyphon charged with water_A new observation for the two phase interaction

2nd International Conference on Sustainable Engineering Techniques

工业技术（总论）

Temimy, Alaa A. B.^1 ; Abdulrasool, Adnan A.^2

Training and Power Research Office, Ministry of Electricity, Baghdad, Iraq^1

Mechanical Engineering Department, Faculty of Engineering, Al-Mustansiriayah University, Baghdad, Iraq^2

关键词: Closed thermosyphon;    Computational fluid dynamics modeling;    Condensate flow;    Flow and heat transfer;    Mass and heat transfers;    Outer diameters;    Two phase;    Volume of fluids;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/518/3/032053/pdf
DOI  :  10.1088/1757-899X/518/3/032053

学科分类：工业工程学

来源: IOP

【 摘 要 】

A three dimensional transient numerical model is done for a Thermosyphon heat pipe to visualize the steam and condensate flow patterns and interaction. The Computational Fluid Dynamics (CFD) model was arranged using Volume of Fluid solution model (VOF)in Fluent. A copper vertical pipe with 14.2mm inside diameter, 400 mm length, and 0.9mm thickness is selected. The heat input varies from (20-120) Watt. The cooling is made with water jacket heat exchanger around the condenser with outer diameter of 55 mm. Filling ratios of (40,50,60,70 and 100) % are tested. All cases show that the classical known flow pattern where the steam flow upward in the core and the condensate flow downward attached to the inner surface of the pipe do not occurs. The simulation results clear out a behavior that both the rising hot steam and the downward condensate flows near the inner pipe wall. So that, both phases face each other near the wall. The high momentum phase continue it flow in its way and shift the other phase from the wall. This flow behavior leads the steam and condensate to flow in a spatial unstable flow upward and downward respectively. The flow continues even when steady state was achieved and create a secondary mass and heat transfer between the phases.