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Abstract
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This paper describes an experimental investigation to study the effect of an Electrohydrodynamic (EHD) phenomenon
on the hydrodynamic behavior of fully-developed film falling upon an inclined plate. A new configuration
of electrodes has been introduced to create the electric field. This field has been applied on the liquid
film by five pairs of overhead high-voltage wire electrodes and the grounded flush mounted plate electrodes
perpendicularly. Transformer oil has been used as the working fluid over Reynolds numbers spanning the range
10–120 in the laminar-wavy regime at three different inclination angles of 15°, 30° and 45°. The experiments
have been further conducted by changing DC high voltage over the range of 11–15 kV for two different wire
electrode heights of 10mm and 14mm that restrict the value of applied voltage. Based on the measured film
thickness, the statistical analysis of the falling film with and without EHD has been performed by image processing
to derive more information such as mean film thickness, wave frequency, and liquid velocity. Film
thickness and wave frequency without the electric field have been validated by other experimental data. The
results indicate that the produced electric field by the wire-plate electrode configuration does not disturb the
original structure of falling film and intensifies the wavy behavior of laminar falling film; therefore, it can be
proposed to either suppress or enhance the heat/mass transfer rate, specially, in falling film absorber. Assuming
the obtained results, the effect of the applied high voltage and the wire electrode height on the interfacial waves
has been also discussed.
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