Abstract:
The paper reports on a fundamental study conducted on R123, to provide a qualitative and quantitative
information for the modelling of multiphase flow motions by electric fields in miniaturized passages
involving nucleate pool boiling.
Miniaturised R123 bubbles, nucleated over a very fine electric wire were studied using a combination of
high-speed digital video camera and Schlieren photographs. Commercial software was also used to accurately
measure bubbles departure size both along the wire, and perpendicular to the wire, average volume,
deformation ratio, and frequency at different electrode voltages or heat fluxes.
It was noticed that there were two regimes of isolated bubbles on which electric field, and heat flux had
similar and quantifiable effects. The first regime was associated with low heat fluxes, and the second regime
is associated with high electric fields. Models were developed to more accurately predict the
electrohydrodynamically (EHD) effects in the isolated nucleate-bubble regimes at both high electric fields,
and low heat flux.
