Showing papers by "Yutaka Asako published in 2002"
TL;DR: In this article, the effective thermal conductivities of compressed Japanese cedars (cryptomeria japonica), which were compressed in the radial direction of the wood, were measured, and the physical mechanism of the heat conduction in the compressed woods was discussed.
26 citations
TL;DR: In this article, the effects of magnetic field on the natural convection, solid phase floatation/sedimentation, liquid/solid interface location, solid melting rate, and the flow patterns are investigated.
Abstract: Transport processes associated with melting of an electrically conducting phase change material (PCM), placed inside a rectangular enclosure, under a low-gravity environment, and in the presence of a magnetic field, is simulated numerically. Electromagnetic forces damp the natural convection as well as the flow induced by sedimentation and/or floatation, and thereby simulate the low-gravity environment of outer space. Computational experiments are conducted for both side-wall heating and top-wall heating under a horizontal magnetic field. The governing equations are discretized using a control-volume-based finite difference scheme. Numerical solutions are obtained for a true low-gravity environment as well as for the simulated low-gravity conditions that are a result of the presence of a horizontal magnetic field. The effects of magnetic field on the natural convection, solid phase floatation/sedimentation, liquid/solid interface location, solid melting rate, and the flow patterns are investigated. It is ...
23 citations
24 Jun 2002
10 citations
01 Jan 2002
TL;DR: In this article, the thermal intumescent characteristics of water glass and sodium metasilicate are investigated using a thermo-gravimetry (TG/DTA) with the heating rate in the range from 1 K/min to 99.9 K/m.
Abstract: A fire barrier material is made of a rubber in which intumescent materials are mixed. Sodium silicate is one of the intumescent materials which intumesces at low temperature. In this report, the thermal intumescent characteristics of water glass and sodium metasilicate are investigated. Thermal intumescent ratio of water glass and sodium metasilicate were measured using a thermo-gravimetry (TG/DTA) with the heating rate in the range from 1 K/min to 99.9 K/min. As the result, it is clarify that thermal intumescent characteristics depend on the heating rate. Thermal intumescent ratio increases with increasing the heating rate. No intumescence was observed under the condition that the heating rate ranges from 1 K/min to 20 K/min.Copyright © 2002 by ASME
6 citations
01 Jan 2002
TL;DR: In this article, the authors used a control-volume-based finite difference scheme to discretize the governing equations of a low-gravity environment using the Lorentz force.
Abstract: Electromagnetic simulation of low-gravity environment has been numerically investigated to study the transport phenomena associated with melting of an electrically conducting Phase Change Material (PCM) inside a rectangular enclosure. Electromagnetic fields are configured in such a way that the resulting Lorentz force can be used to damp and/or counteract the natural convection as well as the flow induced by sedimentation and/or floatation, and thereby simulating the low gravity environment of outer space. The governing equations are discretized using a control-volume-based finite difference scheme. Numerical solutions are obtained for true low-gravity environment as well as for the simulated-low-gravity conditions due to electromagnetic forces. The results show that when the Lorentz force is caused by the presence of magnetic field alone, the low-gravity condition is simulated by the damping effect, which is shown to have a profound effect on the flow field. On the other hand, it is shown that under electromagnetic field simulation, where the Lorentz force is caused by the transverse electric and magnetic fields, it is possible to minimize the flow field distortion caused by the high magnetic field and therefore achieving a much better simulation of low-gravity.Copyright © 2002 by ASME
2 citations