Nucleate Boiling on a Single Site: Contact Angle Analysis for a Quasi-2D Growing Vapour Bubble

Abstract

Heat transfer prediction under boiling condition is still unresolved. In this paper, a basic study on bubble growth is carried out. Recent works show that contact line region plays an important role for heat and mass transfer in nucleate boiling regime. Three dimension experimental set-up lead to a mirage effect which disturbs measurements. To overcome this problem, a new quasi two dimensional experimental set-up is designed. This Hele-Shaw like configuration allows measuring the contact angle and contact line displacement during the bubble growth. A noticeable behavior of the contact angle is observed, and the influence of the sub-cooling level on the bubble growth rate and the contact angle value is studied.

A New Analytical Model for Heat Transfer in Pool Boiling

“…Equation (14) denotes that the larger the active cavity R c , the larger the D b of the bubble diameter at departure, which is consistent with physical phenomena.…”

“…Now from Eqs. (14) and (16), we see that both the bubble diameter at departure D b and the bubble departure frequency f are related to the sizes of active cavities, and (−dN a ) is given by Eq. (2).…”

“…Some notable studies [1][2][3][4][5][6][7][8][9][10][11][12][13] are discussed in this field, which have been performed on N a , which give the functional dependence of N a on heat flux (q) and wall superheat (∆T w ). Recently, Serret et al 14 and Chung and No 15 predicted the wall heat flux using the relation between N a and q. However, the above studies have their own disadvantage.…”