National Space Development Agency of Japan
National Space Development Agency of Japan
National Space Development Agency of Japan
National Space Development Agency of Japan
Toshiba Corporation
Toshiba Corporation
Toshiba Corporation
Toshiba Corporation
出版者
宇宙開発事業団
出版者(英)
National Space Development Agency of Japan (NASDA)
The experiment of Thermally Driven Flow Unit (TDFU) under micro-gravity was planned by NASDA as a part of Second International Micro-Gravity Laboratory (IML-2) scheduled to be launched in 1994. The purpose of this experiment is to establish the design concept of liquid reorientation and transfer under micro-gravity condition, which is required for the component design of on going development two-phase fluid loop thermal management system (especially for accumulator/reservoir design). Although it is known that liquid reorientation is achieved by capillary force (surface tension), the design parameter such as capillary core structure, wall material and kind of treatment are not well put in order. In order to support TDFU design, the model for aircraft test was prepared, whose size, material and surface treatment are the same as that of TDFU. This model was composed of copper container, polycarbonate window, copper core and water as liquid. The copper surfaces are treated so as to be reduced contact angle with water (to have good wettability). Due to this design, water flows into the core under micro-gravity condition by capillary force and/or surface tension. Six types of core shape (core plate) -parallel and tapered- were prepared to obtain the effect of (1) core shape. Also observed are effects of (2) acceleration direction before micro-gravity condition, (3) water quantity and (4) existence of non-condensible gases. It is confirmed from this experiment that, among other parameters core shape is most dominant for liquid reorientation, ie., it is observed that, as core angle is made larger and as average core separation (equivalent to capillary gap) is made smaller, the liquid reorientates to the core more easily and vapor to out side of the core.