International Journal of Heat and Mass Transfer, Vol.54, No.13-14, 2962-2974, 2011
Interfacial heat transfer of condensing bubble in subcooled boiling flow at low pressure
The interfacial heat transfer coefficient is an important parameter for the analysis of multi-phase flow. In subcooled boiling flow, bubbles condense through the interface of phases and the interfacial heat transfer determines the condensation rate which affects the two-phase parameters such as void fraction and local liquid temperature. Thus, the present experiments are conducted to correlate the interfacial heat transfer coefficient at low pressure in the subcooled boiling flow. The local liquid temperature is measured by microthermocouple and the bubble condensation rate is estimated by orthogonal, two-image processing. The condensate Nusselt number, which is a function of bubble Reynolds number, local liquid Prandtl number, and local Jacob number, is obtained from the experimental results. The bubble history is derived from the newly proposed correlation and the condensate Nusselt number is compared with the previous models. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords:Subcooled boiling;Condensation Nusselt number;Bubble history;Two orthogonal image processing