Motion of Vapor Bubbles in Subcooled Heated Channel

Bubble and boundary layer behaviour in subcooled flow boiling

“…With increasing mass flux the bubble lifetime decreases and it can be seen, that for high mass fluxes (G > 1500 kg·m −2 ·s −1 ) no bubbles reach a lifetime of more than 1.5 ms. The results of the liquid mass flux variation show good agreement with the findings of other authors like Gunther [1], Akiyama and Tachibana [24] or Zeitoun and Shoukri [25], who also studied the bubble lifetime during subcooled flow boiling. The reason for the smaller size distribution at higher convective mass fluxes is the reduced temperature in the thermal boundary layer and the augmentation of turbulence in the cross flow.…”

Measurement of bubble detachment diameters from the surface of the boiler heat exchanger in a domestic central heating system

“…More models have been developed for predicting the bubble detachment diameters under stagnant conditions, such as the approach originally suggested by Scriven [8] and later adapted by Jones et al [9] that are based on the symmetric phase growth controlled by heat and mass transfer. Other models such as that by Akiyama and Tachibana [10] were developed for predicting bubble detachment diameters in boiling conditions. Such models were developed for modelling bubble nucleation and require a comprehensive knowledge of the surface conditions and the bubble nucleating time.…”

An experimental study on bubble rise path after the departure from a nucleation site in vertical upflow boiling

“…Sufficient understanding of the complex interaction between the vapor bubbles and turbulent liquid flow is hence important to develop reliable 0894 prediction methods for the heat transfer rate in flow boiling. Thus, extensive visual observations of vapor bubbles in vertical upflow boiling were conducted in subcooled conditions [1][2][3][4][5][6][7][8][9] and also in saturated or slightly subcooled conditions [10][11][12]. In these experiments, the important bubble parameters including the size, shape, growth and collapse rates, population, frequency and trajectory were measured in varied conditions of working fluid, system pressure, liquid subcooling, applied heat flux and inlet velocity.…”