| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2002: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Research Abstract |
1.A charged water-drop in oil to which uniform electric field is applied collides alternately with an electrode plate, and reciprocates between electrode plates. The collision can be applied to the augmentation of freezing nucleation of a supercooling water-drop. The experimental study of the freezing initiation of a double-distilled water drop of 4mm in diameter is conducted,in silicone oil of -5〜-4℃, under condition of 0.22 and 0.28MV/m in electric field strength. A single water-drop that collides with a transparent electrode of indium-tin oxide coated soda lime glass is photographed from the other side of the drop with a high-speed video camera. A contact area between the drop and the electrode plate, time and position in which freezing initiates and freezing progress in the drop are clarified. As a result, drops of 80-85% initiate freezing between the time of maximum contact area and the departure from the electrode plate. Freezing initiation is observed not only in the vicinity of the solid-liquid boundary and three-phase boundary, but also in the vicinity of the liquid-liquid boundary. It becomes hard for freezing to initiate, as the retention particle diameter of the filter for silicone oil is reduced. There is a possibility that particles in the silicone oil contribute to the freezing initiation in the electric field.
2.Double-distilled water of 0℃ is injected at the velocity of 0.34-0.53m/s through a nozzle, into silicone oil of -5℃ with uniform electric field. The changes in the initiation-ratio, of freezing and freezing-ratio of drops are obtained in the direction of depth.
It will be necessary to clarify the above-mentioned particles, and to clarify the influence of the electric field on the activation of particles for freezing nucleation.
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