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Title Transcription
カザン サイセツブツ ノ チンコウ ソクド ト ソノ イギ
Title Alternative (English)
Settling velocity of volcaniclastics and its significance
File
language
jpn
Author
Masumoto, Aki
Nakayama, Katsuhiro
Description
Volcaniclastics falling velocity is estimated by measurements with settling tube.Samples are obtained from the Pliocene Ohtani and Souri volcanic ash layers in the Tokai Group.ln terms of content,volcanic glass and pumice predominate in these layers.In the Ohtani volcanic ash,mean specific gravity of volcanic glass is 2.25 which is higher than that of pumice (1.15).In the Souri volcanic ash,mean specific gravity of volcanic glass and pumice suggests 2.25 and 1.50 respectively.Particle falling velocity of the Ohtani and Souri volcanic ash can be described by following formulas.
Cd=26+24/Re,W=[−9η+{81η^<2>+156pa^<3>(σ−p)g}^<0.5>]/39pa
Cd=3.4+24/Re,W=[−18η+{324η^<2>+81.6pa^<3>(σ−p)g}^<0.5>]/10.2pa
whereσand p are the particle and fluid densities respectively,g is the acceleration due to gravity,ηis fluid dynamic viscosity,Re is grain Reynolds number,a is the particle radius,Cd is non-dimensional drag coefncient,and W is the falling velocity.These formulas mean the transition to turbulence is promoted at
a lower Reynolds number than for the corresponding smooth spherical particles.More poorly sorted bedforms can be explained by these formulas,which suggest that more varied grains in diameter can be deposited under a small range of falling velocity.
Journal Title
島根大学地球資源環境学研究報告
Volume
14
Start Page
37
End Page
41
ISSN
13439774
Published Date
1995-12-25
NCID
AA11455176
DOI(SelfDOI)
Publisher
島根大学総合理工学部地球資源環境学教室
Publisher Aalternative
Department of Geoscience, Interdisciplinary Faculty of Science and Engineering, Shimane University
NII Type
Departmental Bulletin Paper
Format
PDF
Text Version
出版社版
OAI-PMH Set
Interdisciplinary Graduate School of Science and Engineering
Remark
12-14,16+ / 1993+
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