反町 健一 川崎製鉄(株), 技術研究本部, 製鋼研究室長
FUJIMOTO Hitoshi Kyoto University, Faculty of Engg., Assistant, 工学部, 助手 (40229050)
TAKUDA Hirohiko Kyoto University, Faculty of Engg., Lecturer, 工学部, 講師 (20135528)
SORIMACHI Ken-ichi Kawasaki Steel Corp, Steel labo.Director
|Budget Amount *help
¥8,100,000 (Direct Cost : ¥8,100,000)
Fiscal Year 1993 : ¥1,500,000 (Direct Cost : ¥1,500,000)
Fiscal Year 1992 : ¥6,600,000 (Direct Cost : ¥6,600,000)
We believe that the intially anticipated purpose of this research has been attained for the most part. This research basically covers a few special fields such as computational fluid dynamics, two-phase flow theory, heat transfer and numerical analysis, and therefore the research consists of the three stages. The results obtained here are summarized as follows :
First, the nozzle frow of a two-phase mixture composed of air and water droplets, the flow mechanism of the two-phase free jet and the flow behavior of the two-phase freejet impinging on a flat plate have been unmerically analyzed. However, the deformation process of droplets impinging even a flat plate with an ordinary room temperature has not yet been clarified regardless of the challenge of many researchers. Hence, the numerical model to assess the deformation process has been established by our research group. Also, it has been confirmed that the deformation process calculated by the present model is in fairly good agreement
with experimental data. The paper concerned with this result has been submitted to the Trans. ASME Journal of Fluids Engineering for publication.
Second, it has been experimentally clarified that the deformation behavior of droplets impinging on a hot plate surface beyond the Leidenfrost point can be classified into three kinds of patterns. Basically, the droplet deformation behavior may be classified into two kinds of patterns according to whether the droplet crushes or not after the collision with the plate surface. Taking into account the configuration of droplet of the case where the droplet does not crush, there seems to be three kinds of patterns. The condition whether the droplet crushes or otherwise is dependent not only upon the We number, but also upon the surface temperature and properties etc.. Also, we have clarified the overall mechanism of the crushed and deformation for each pattern, although it is not theoretical but empirical.
Third, the estimation of cooling process of a hot plate surface beyond the Leidenfrost temperature by water spray have considered so that the assess of the cooling intensity is available for an actual operation in the secondary cooling zone of the continuous casting process. In order to do so, the high temperature metal surface has been cooled by many kinds of water sprays of which the water flow rate is entirely different from each other and each temperature process with time has been measured by the CA thermocouples. Thereby, the predictable modeling for cooling process of a hot plate by a water spray has been constructed by the inverse analysis.
Finally, we think that there are a number of problems which remains unsolved and wish to promote the present investigation further. Less