Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 0-89116-130-9

International Heat Transfer Conference 6
August, 7-11, 1978, Toronto, Canada

EXPERIMENTAL STUDY ON DROPWISE CONDENSATION − EFFECT OF MAXIMUM DROP SIZE UPON THE HEAT TRANSFER COEFFICIENT

Get access (open in a dialog) DOI: 10.1615/IHTC6.280
pages 477-482

Abstrakt

A wiper made of silicone rubber was used to remove all the drops on the condensing surface simultaneously and periodically. The maximum drop size was controlled at experimenters' will and a uniform state of condensation was established over the entire surface.
Two kinds of measurements were carried out. The first one was a periodical steady-state heat transfer measurement. The maximum drop size was changed by varying the sweeping period of the wiper and the rate of drop growth and the time averaged heat transfer coefficient were measured. The second was a transient measurement. The variations of the temperatures at the condensing surface and inside the condensing block were measured, and the transient heat transfer coefficient at the surface was calculated. At the same time the process of drop growth was recorded with a high-speed movie camera, and the maximum drop size at every instant was related to the transient heat transfer coefficient. It was recognized that an extremely high heat transfer coefficient (higher than 1 MW/m2K) was realized on the condensing surface just after it was cleared off by the wiper blade.
The results obtained serve well to give a quantitative explanation to the mechanism of dropwise condensation.