Numerical and Experimental Studies on Circulation of Working Fluid in Liquid Droplet Radiator

Paper number

IAC-05-C2.6.04

Author

Dr. Tsuyoshi Totani, Hokkaido University, Japan

Coauthor

Mr. Takuya Kodama, Hokkaido University, Japan

Coauthor

Mr. Kensuke Watanabe, Hokkaido University, Japan

Coauthor

Mr. Kota Nanbu, Hokkaido University, Japan

Coauthor

Associate Professor Harunori Nagata, Hokkaido University, Japan

Coauthor

Prof. Isao Kudo, Japan

Year

2005

Abstract

The liquid droplet radiator (LDR) is an important candidate for disposing of large quantities of waste heat from a large space structure, which handles high power (from megawatts to gigawatts) such as space solar power satellites (SPS).  As characteristics on the circulation of working fluid have not been clarified enough in the previous studies, we have been studied this matter.

The LDR in the present work consists of a droplet generator, a droplet collector, a gear pump and a bellows-type pressure regulator.  The equipments that volume of working fluid changes in are the droplet collector and the bellows-type pressure regulator.  Rotation speeds of the droplet collector and the gear pump, and pressure put on the bellows-type pressure regulator are controlled to make the flow rate constant.

A simulation model on the circulation of working fluid in LDR was built.  The behavior of the circulation of working fluid calculated from the model was compared with that obtained from experiments in the following two cases.  In case (a), the behavior of the circulation of working fluid after the flow rate was changed was compared.  In case (b), the behavior of the circulation of working fluid after a part of the working fluid in the droplet collector was moved to the bellows-type pressure regulator was compared.  Case (a) corresponds to the case that amount of waste heat removed from a large space structure changes.  Case (b) was carried out in order to examine whether LDR in the present work has the capability to stabilize the circulation of working fluid by itself.

Results calculated from the simulation model have been corresponding well to those obtained from the experiments in both of case (a) and (b).  The mechanism of the circulation of working fluid in LDR has been clarified.  It is obtained that the simulation model built in the present work can forecast the behavior of the circulation of working fluid in the LDR.  In case (b), LDR returned without control to the state of circulation before a part of the working fluid in the droplet collector was moved to the bellows-type pressure regulator.  This result makes it clear that the LDR used in the present work has the capability to stabilize the circulation of working fluid by itself.  It is concluded that LDR system used in the present work is easy to control the flow rate of the circulation.

Abstract document

IAC-05-C2.6.04.pdf

Manuscript document

IAC-05-C2.6.04.pdf (🔒 authorized access only).

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