Oscillation-controlled heat-transport tube (heat transfer coefficient in tubes in heating and cooling regions)

✍ Scribed by Shin, Hung-Tae ;Nishio, Shigefumi

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 199 KB
• Volume: 27
• Category: Article
• ISSN: 0096-0802
• DOI: 10.1002/(sici)1520-6556(1998)27:6<415::aid-htj2>3.0.co;2-i

✦ Synopsis

In the present study, heat transfer coefficients of oscillatory flow at inner surfaces of the heating and cooling regions of oscillation-controlled heat-transport tubes (OCHTs) are investigated numerically. The numerical simulation is conducted under the following three conditions for the tube walls at the heating and cooling regions: isothermal, extremely thin, and actual wall systems. Based on the numerical results and Hausen's correlating equation for laminar flow heat transfer in tubes, a correlating equation of the heat transfer coefficient is developed which can be generally applied to these three conditions. Next, using this correlating equation and the authors' simplified model of overall thermal resistance in OCHTs, heat-transport rates are predicted, and it is found that the predicted results are in good agreement with the numerical results. Finally, numerical simulation is conducted also to compare the heat-transport rates of OCHTs with those of the conventional forced circulation type under the same pumping power. The results indicate that there exist oscillatory flow regions in which the heat-transport rate of the phase-shifted OCHTs is larger than that of the conventional circulation type.