2004 Fiscal Year Final Research Report Summary
Study on improvements of cloud microphysics modeling and control of artificial cloud generation in the huge vertical shaft
| Project/Area Number |
14350270
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
水工水理学
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| Research Institution | CHUO UNIVERSITY |
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Principal Investigator |
YAMADA Tadashi Chuo University, Faculty of Science and Engineering, Professor, 理工学部, 教授 (80111665)
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| Co-Investigator(Kenkyū-buntansha) |
KASHIYAMA Kazuo Chuo University, Faculty of Science and Engineering, Professor, 理工学部, 教授 (10194721)
HIRANO Hirokazu Chuo University, Faculty of Policy Studies, Professor, 総合政策学部, 教授 (80256023)
FUJIYOSHI Yasushi Hokkaido University, Institute of Low Temperature Science, Professor, 工学部, 教授 (40142749)
OHTA Schio Hokkaido University, Faculty of Engineering, Professor, 工学部, 教授 (00100058)
FUJITA Mutsuhiro Hokkaido University, Faculty of Engineering, Professor (80001139)
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| Project Period (FY) |
2002 – 2004
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| Keywords | Aerosol / Experiment of cloud microphysics / Cloud microphysics model / Updraft velocity / Artificial rainfall / Numerical simulation / Chemical composition / Condensation growth |
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| Research Abstract |
Actual scale experiment of cloud microphysics in mine was carried out. This study aims at revealing cloud microphysical mechanism of generation and development processes of cloud and rainfall. In this experiments, large size fan which generate updraft was placed on the top of vertical shaft and clouds are generated artifitially by controlled updraft. Moreover, several kinds of solution are sprayed at the bottom of vertical shaft. This make it possible to controll chemical composition, solution consistency and number density of aerosol flowing into the vertical shaft. Experiment result such as vatiation of meteorological elements with height and changes in air condition at phase change from vapor to cloud particle could have been obtained. Those experimental data have compared with simulation results by newly developing rainfall simulation model by our research group, which consider effects of aerosol in the air.Following results have been obtained by experiment during reserach period.
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.Experiment controlling inflow air (auch as aerosol number denisty, velocity of updraft) into vertical shaft :
(1)Vertical dsitribution of aerosol number density were measured. Increase of number densityaround elevation of cloud base are observed. Additionally, condensational growthing process of cloud particle as those flow up in vertical shaft were observed. (2)In case of spraying solution at the bottom of vertical shaft, the number of particles with small diameter increase at the top of shaft, meanwhile the number of particles with large diameter decrease. (3)As aerosol number density spraied at the bottom increase, amount of generated cloud water also increase. However, if number denisty of aerosol is too much, amount of generated cloud water intends to converge to constant value. (4)Amount of cloud water increase as updraft velocity is high. Then relations between amount of cloud water and updraft velocity is linear.
2.Temperature distribution in vertical shaft are different before and after generation of cloud. Temperature lapse rate at elevations higher than cloud base is smaller that saturated-adiabatic lapse rate after cloud generation. This measurement result could not be duplicated by existing simulation model. On the other hand, this phenomena could be duplicated by our newly developed simulation model considering effect of aerosol. Less
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