Hosei Nagano

This paper reports design, fabrication, and experimental results of a loop heat pipe (LHP) as a heating device for batteries of electric vehicles. Usually, LHPs are used as a cooling device. In this study, however, the LHP is used as a heating device by attaching battery blocks which are the heating target, to the condenser of the LHP. A new transient analytical model was also constructed using the implicit method, which is a multidimensional extension of the Newton–Raphson method. The analytica

An experimental investigation was conducted on the capillary limit of a miniature loop heat pipe with multiple evaporators and multiple condensers. Tests were conducted under various operating conditions: 1) heat load to one evaporator only; 2) even heat loads to both evaporators; 3) no temperature control of either compensation chamber; 4) controlling the temperature of one or both compensation chambers using thermoelectric devices; 5) placing the loop in a horizontal position with evaporators

The concept, detailed design, fabrication, and test results of a reversible thermal panel, which is a new, passive, and lightweight 100 W-class deployable radiator with an environment-adaptive function, is described. The reversible thermal panel changes its function reversibly from a radiator to a solar absorber by deploying/stowing the radiator/ absorber reversible fin upon changes in the heat dissipation and thermal environment, and is effective for the thermal control of high power density sm

This paper reports the development of an experimental small loop heat pipe with polytetrafluoroethylene (PTFE) wicks. Three kinds of PTFE porous materials were fabricated, and their wick properties were evaluated. It was clarified that the peak pore radii of the PTFE porous materials ranged from 0.8 to 2:2 � m, and their porosities ranged from 27 to 50%. A small loop heat pipe with PTFE wicks was designed using these properties, and an experimental small loop heat pipe, for which the wick in an

Thermophysical properties of a new material-a graphite sheet, which has characteristics of high thermal conductivity, anisotropy, lightweight and flexibility-have been measured in order to apply this sheet to a spacecraft thermal control material. The following measurements were performed: 1) The thermal diffusivities in the in-plane and out-of-plane directions were measured over the temperature range from 100 to 350 K using a laser heating ac calorimetric method. 2) The specific heat and the to

This paper presents fabrication and testing of a multiple-evaporator and multiple-condenser loop heat pipe (MLHP) with polytetrafluoroethylene (PTFE) porous media as wicks. The MLHP has two evaporators and two condensers in a loop heat pipe in order to adapt to various changes of thermal condition in spacecraft. The PTFE porous media was used as the primary wicks to reduce heat leak from evaporators to compensation chambers. The tests were conducted under an atmospheric condition. In the tests t