NUF-EHD 유동을 이용한 마이크로 펌프 및 혼합기 개발

Abstract

In the first part of the thesis, a new electrohydrodynamic (EHD) pumping method for dielectric liquids is presented. These methods rely on the non-uniformed-field EHD (NUF-EHD) flow generated by electric-field dependent electrical conductivity (Onsager effect). A polar additive plays an important role in enhancing the field-dependency of conductivity. When ac voltage is applied, a fast and regular flow was produced around electrodes. Flow speed is proportional to cube of electric-field strength and inversely to applied frequency. The experimental results showed good agreement with numerical analysis based on our theoretical model. In the second part of the thesis, a preliminary numerical investigation is performed to apply the NUF-EHD flow to improve the mixing of fluids. The validity of numerical method is confirmed by comparing the numerical and experimental results for the flow fields around periodic rectangular blocks. The numerical results suggest that the NUF-EHD can significantly enhance the mixing of two fluids.