流体物理学ゼミナール2005/11/21


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_/ 流体力学セミナー 2005 No. 13
_/ (数理研 21世紀特別講演と共催)
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_/ 日 時 : 05年 12月 5日 (月) 15:00〜16:30
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_/ 場 所 : 京大数理研 009号室
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_/ 講 師: A.D.D. Craik 氏 (University of St.Andrews)
_/ 題 目: On the development of singularities in linear dispersive systems
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_/ 内 容 :
_/ Benilov, O’Brien & Sazonov (2003) and Benilov (2004) describe “a new
_/ type of instability” in a liquid film inside a rotating cylinder.
_/ Though their linear systems support only neutrally-stable modes, they
_/ find explosive disturbances which become singular after a finite
_/ time. They suggest that this result casts doubt on the reliability of
_/ modal analysis for prediction of instability; and they claim that
_/ “Such cases have never been described in the literature, and they are
_/ probably extremely rare.” Here, other examples are given, some of
_/ which have been known (though not well-known) for many years. A
_/ common feature of all these singularities is a local phase
_/ synchronisation of short-wave modes; but the configuration of Benilov
_/ et al. has the additional feature of eigenfunctions that exhibit very
_/ large changes in amplitude within the spatial domain. The relevance,
_/ or not, of such singularities to real physical systems is discussed.
_/ (J.Fluid Mech. (2005) Vol.538, 137–151)
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世話人:大木谷 耕司(京大数研)、藤 定義(京大理)、松本 剛(京大理)、
山田 道夫(京大数研)
アドバイザー:小森 悟(京大工)、藤坂博一(京大情報学)、
船越 満明(京大情報学)、水島 二郎(同志社大工)、余田 成男(京大理)
連絡先:ohkitani@kurims.kyoto-u.ac.jp
メールリスト連絡先: semi-adm@kyoryu.scphys.kyoto-u.ac.jp

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