Convective Boiling Between 2D Plates: Microgravity Influence on Bubble Growth and Detachment

Abstract

The experiment detailed in this paper presents results obtained on the nucleation, growth and detachment of HFE-7100 confined vapour bubbles. Bubbles are created on an artificial nucleation site between two-dimensional plates under terrestrial and microgravity conditions. The experiments are performed by varying the shear flow by changing the convective mass flow rate, and varying the bubble nucleation rate by changing the heat flux supplied. The experiments are performed under normal (1 g) and reduced gravity (μg). The distance between the plates is equal to 1 mm. The results of these experiments are related to the detachment diameters of bubbles on the single artificial nucleation site and to the associated effects on the heat transfer by the confinement influence. The experimental device allows the observation of the flow using both visible video camera and infrared video camera. Here, we present the results obtained concerning the influence of gravity on the bubble detachment diameter and the images of 2D bubbles obtained in microgravity by means of an infrared camera. The following parameters: nucleation site surface temperature, bubble detachment diameter and bubble nucleation frequency evidence modifications due to microgravity.