Bubble growth on a smooth metallic surface at atmospheric and sub-atmospheric pressure

Bubble growth rate is one of the most important parameters required for development accurate mechanistic nucleate boiling heat transfer models. It also very understanding hydrodynamic forces and mechanism bubble departure. This paper presents an experimental study on measurements in saturated pool deionized water a plain copper surface at atmospheric sub-atmospheric pressure. The were conducted using high-speed, high-resolution camera with microscopic lens. mechanisms are discussed, while microlayer evaporation has been evaluated discussed measured curve. estimated contribution to single about 70 %, latent (evaporation) total from 30 %. remaining % due other mechanisms, i.e. conduction convection. These values obtained based analysis curve only agreed some researchers who local integrated sensors or infrared thermography. detailed measurement techniques cannot be used thick block tested current study, which was by many literature representative industrially surfaces. found that departure pressure static balance between tension buoyancy pressure, it liquid inertia forces. did not have significant effect characteristics dynamic contact angle, instantaneous images bubble. concluded force prediction diameter should when two equal, occurred time less than angle 45. In models, recommended moment forms neck 900 (underestimation force). commonly homogeneous models indicated applicable boiling, allowance must made fact degree superheat varies during period.