Rezumat
CZU 532.5+537.571
The paper presents experimentally measured velocity distributions of electrohydrodynamic (EHD) flows and corresponding current-voltage characteristics in a wide voltage range (from 1 up to 27 kV) at both polarities. Measurements were carried out by the particle image velocimetry (or PIV) with a high spatial resolution (about 50 values per mm2). An organic dielectric – olive oil – was used as working liquid. The detailed description of the EHD-flow structure at various voltages as well as axial and profile velocity distributions are presented. A special case was observed when there were two reversely directed vortexes caused by the concurrent effect of two different mechanisms of charge formation. The velocity distribution in the section along the sharpened electrode was shown to be non-uniform. The results can be used for the quantitative verification of computer models of EHD flows due to high measurement accuracy.
Keywords: electroconvection, electrohydrodynamics, injection, low-conducting liquid, velocity distribution.