| Budget Amount *help |
¥11,200,000 (Direct Cost: ¥11,200,000)
Fiscal Year 2002: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2001: ¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2000: ¥6,600,000 (Direct Cost: ¥6,600,000)
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| Research Abstract |
On the application of high DC electric fields to some insulating oils, a fiuidjet with a velocity of about 1ms^<-1> is generatedfromthepositive electrode due to electrohydrodynamic(EHD) effect. In this process, the electric energy is directly converted to kinetic energy of the fluid. The purpose of this study is the analysis of jet flow and development of new fluid devices. The flow patterns of EHD jet is discussed in relation to the geometry of vessel, electrode arrangement, field strength, and fluid properties. The speed of jet flow at a given field strength increases with decreasing electric conductivity and viscosity of fluid This finding provides a formulation method of good working fluids. By controlling the direction and speed of jet flow, new fluid devies are designed such as dielectric fluid motors, inkjet nozzles, micropumps, and elerctrorheological(ER) devices. The fluid motors simply consist of electrodes, rotor, and working fluids. Since the magnetic fields are not required, the dielectric fluid motors have various kinds of advantages. For example, the motors by the use of flexible and light materials are possible and this can serve to construct soft micromachine. When subjected to high DC fields, the extra stresses across the interfaces are induced and the continuous evolution of free surface from the nozzle exit can take place. The inkjet units consisting of needle electrode and capillary are developed without piezoelectric transducers. The fluids which are sandwiched in electrodes with flocked fabrics show viscosity increase under electric fields. The ER effects are applicable to mechanical devices such as clutch and shock absorber because the local fluidity is actively controlled. The EHD jets are very attractive in application to new fluid devices.
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