MURAKAMI Masahide Associate Professor, University of Tsukuba, Institute of Engineering Mechanics, 構造工学系, 助教授 (40111588)
YOSHIZAWA Yoshimasa Professor, University of Tsukuba, Institute of Engineering Mechanics, 構造工学系, 教授 (30029392)
|Budget Amount *help
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1989: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1988: ¥1,300,000 (Direct Cost: ¥1,300,000)
The main objective of this study is to get better insight into a mechanism of vapor condensation and/or evaporation associated with heat transport through fluid media. To clear this phenomenon is important in the spacecraft thermal design and management, such as transpiration cooling, two-phase flow in a heat rejection system, or heat pipes, etc. The study is composed of three subjects; experiment of vapor condensation in an enclosure, experiment of plane shock wave propagating through vapor-liquid two-phase media, and numerical simulation of a vapor flow field.
In the first subject, we could visualize the vapor flow field in the laser holographic interferogram in the first time, and make clear the structure of an interfacial layer which divides a pure vapor from a noncondensable gas. Density and temperature distributions in the flow field were also obtained from these interferograms. This information will be important for improvement of a design of heat pipes or fluid loops.
In the seco
nd subject, a flow field immediately after a shock wave passage by schlieren photograph, laser holography, and pressure and temperature gages. Heat transport in the flow field is strongly influenced by thermodynamic condition of a tube wall, as well as shock intensity and fluid medium used in the experiment. The characteristic stripe patterns observed in the flow field indicates a strong clue that a trace of condensate matters or fine droplets which were created by a shock passage, although these must be verified by some other means. We will make further effort to detect a true content of the stripe patterns. Other characteristics are that shock intensity is much weaker than that predicted Rankine-Hugoniot relation, heat transfer rates to the tube wall is much larger than that predicted by frictional heating of a pure gas.
In the third subject, phenomenological equations of transport phenomena are employed for expressing the two-dimensional flow field, and numerical simulation were successfully conducted for slow vapor flow in the condenser section of thermosyphon. However, an attempt to revise these governing equation system for simulating the flow field behind a shock wave is still in process because of no condensation modeling suitable to the current experimental condition. Less