抄録
This paper presents the experimental data concerned with the influences, of cavitation on the characteristics of the fluidic element. With reference to each degree of cavitation as defined by a cavitation number K, the variations of the control port pressure Hco, the vortex center pressure Hvor, the output port pressure Po and the attachment length La are investigated.
The dimensions of the fluidic element used are: main nozzle width bs: 4mm (or 3mm), aspect ratio: 2.0 (or 2.7), offset D: (0-3.0)×bs and wall angle α: 15°. Using water of 21∼22°C as the operating fluid, the studies were performed under the conditions of main jet velocity vs=4.0∼33.0m/s and various offsets.
The following experimental results are obtained:
(1) Cavitation appears and develops in the both shear layers of the jet. It appears first on the attached side and later on the unattached side. When the Reynolds number is increased further, the both leading locations of cavitation inception move upstream.
(2) Hco and Hvor hold linearity with vs2/2g and La is also constant until cavitation develops widely and swallowed by the vortex.
(3) The ratio of the output pressure to supply pressure does not reduce so soon as cavitation appears, but falls in the higher speed region because of the increase of cavitation loss.
