International Journal of Applied Electromagnetics and Mechanics - Volume 33, issue 3-4

Authors: Tsukiji, Tetsuhiro | Yoshida, Kousuke | Yokoyama, Kazuya

Article Type: Research Article

Abstract: We cause a low-molecular-weight liquid crystal in the nematic phase to flow between parallel plate electrodes at a constant rate. Under electric fields (in the range 0–1.0 kV/mm), magnetic fields (in the range 0.0–2.0 T, where 1 T=10000 G), and both magnetic and electric fields, we measured changes in liquid crystal flow resistance and orientation. We also estimated the crystal orientation by measuring the brightness of light through the crystal to investigate the relationship between pressure …drop and orientation. As results, the pressure drop increases as electric and magnetic field intensities increase, and remains constant at E > 0.6 kV/mm. Under application of an electric field, the brightness of light through the liquid crystal increases with increasing rates of pressure in the range 0–0.4 kV/mm. Show more

Keywords: Liquid crystal, electric field, magnetic field, parallel plate electrodes

DOI: 10.3233/JAE-2010-1297

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1653-1659, 2010

Authors: Tsujita, Teppei | Kobayashi, Masanori | Nakano, Masami

Article Type: Research Article

Abstract: ER suspension behaves like a Bingham fluid having yield stress, which can be rapidly changed in a reversible manner by applying electric field. By taking the advantage, Braille display using micro actuators driven by the suspension is developed. The micro actuators are fabricated by photolithography and allocated three dimensionally based on requirement specification which are determined experimentally. The system is integrated in small size and has high reliability since the valves consist of no moving components. …In order to evaluate actuation of a micro actuator controlled by the valves, an experiment for displaying six tactile pins is performed. Show more

Keywords: Electrorheological suspension, Micro ER valve, Non-Newtonian fluid, Micro machine

DOI: 10.3233/JAE-2010-1298

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1661-1669, 2010

Authors: Ido, Yasushi | Sasaki, Motoyasu

Article Type: Research Article

Abstract: A lattice Boltzmann method for two-phase flows with large density ratios proposed by T. Inamuro, et al. (2004) is extended in order to simulate behavior of magnetic fluids in the presence of steady weak magnetic field. A new additional term corresponding to the Maxwell stress tensor is introduced into the distribution function. The additional term is determined by using the Chapman-Enskog expansion. Surface deformation of a magnetic fluid drop in the presence of magnetic field is …simulated by using this method, and the results are qualitatively agree well with the experimental results. Show more

Keywords: Lattice Boltzmann method, magnetic fluid, Chapman-Enskog expansion

DOI: 10.3233/JAE-2010-1299

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1671-1676, 2010

Authors: Kakunuma, Yasuhiro | Tanaka, Hidetaka | Aoyama, Tojiro | Anzai, Hidenobu

Article Type: Research Article

Abstract: Electro-rheological gel (ERG) is a functional elastomer, which changes its surface adhesive property according to the intensity of electric field. In this study, ERG is applied to multiple-disk brake element to realize both simplification of structure and wide range of controlled brake torque. First, static performance of ERG multiple-disk brake (ERG-MDB) is evaluated experimentally. It is clear that a generated brake torque depends on an electric field and the number of layer of ERG. ERG-MDB with …6 layers shows 5 times brake torque as high as that with 1 layer. Second, considering the dynamical model of the ERG-MDB, dynamic performance is investigated through the forced vibration test. The result shows that dynamic damping and stiffness coefficients are changed widely according to applied electric field. Show more

Keywords: ER gel, Electro-adhesive effect, brake element

DOI: 10.3233/JAE-2010-1300

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1677-1683, 2010

Authors: Nishida, Hitoshi | Shimada, Kunio | Ido, Yasushi

Article Type: Research Article

Abstract: We investigated the effect of the flow direction of abrasive particles and magnetic clusters on polishing of an inner capillary wall by magnetic compound fluid (MCF) flow. We used an experimental system for polishing inner capillary walls by controlling the MCF flow rate and the rotational speed of the magnetic field. We clarified the relationship between the traces left in the capillary and the flow direction of the abrasive particles and the magnetic clusters, which influences …the polishing. Show more

Keywords: Polishing, inner capillary wall, magnetic compound fluid, flow rate, magnetic field, magnetic cluster

DOI: 10.3233/JAE-2010-1301

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1685-1690, 2010

Authors: Chen, Mingji | Pei, Yongmao | Fang, Daining

Article Type: Research Article

Abstract: Composite lattice grids reinforced by glass fibers and carbon fibers filled with spongy materials can be designed as lightweight microwave absorbing structures (MASs). In the present paper, a computational method for scattering from 2-Dimensional (2-D) Kagome lattice grids has been developed. Reflectivity calculated by this method is in good agreement with the experiment. Microwave absorbing structures with 2-D Kagome lattice grids are predicted to be more efficient than those with square lattice grids in microwave absorbing …as well as load bearing. Show more

Keywords: Microwave absorbing structure, composite lattice grid, reflectivity

DOI: 10.3233/JAE-2010-1302

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 1691-1694, 2010