Microgravity Fluid Physics & Heat Transfer

ISBN Print: 978-1-56700-147-1

ISBN Online: 978-1-56700-444-1

INTERFACIAL MASS TRANSFER STUDIES ON VAPOR BUBBLES IN MICROGRAVITY

DOI: 10.1615/MFPHT-1999.90
pages 72-79

Аннотация

Experiments for the investigation of the interfacial heat and mass transfer have been performed in micro­gravity using the German drop tower and have been operated onboard the IML2 (1994) and LMS (1996) Space-Lab-Missions in the BDPU (Bubble, Drop and Particle Unit), ESA's multi-user facility for fluid physics experiments. During these experiments the growth and collapse of free vapor bubbles were ob­served at various liquid temperature levels and over very long periods up to 300 seconds for the first time. The experimental set-up allowed the control of the liquid supersaturation before the bubbles were initiated at a miniaturized heater. Therefore it was possible to perform a systematic parametric study of the governing factors like fluid temperature and supersaturation of the liquid. The measured curves for vapor bubble growth are in good agreement with our numerical simulation. Based on this numerical model the kinetic coefficients for the evaporation and condensation according to Hertz-Knudsen have been derived from the experiment data.