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In fluid dynamics the Eötvös number (Eo), also called the Bond number (Bo), is a dimensionless number measuring the importance of surface tension forces compared to body forces and is used (together with Morton number) to characterize the shape of bubbles or drops moving in a surrounding fluid. The two names commemorate the Hungarian physicist Loránd Eötvös (1848–1919) 〔 〕 〔 〕 〔 〕 〔 〕 and the English physicist Wilfrid Noel Bond (1897–1937),〔〔 〕 respectively. The term Eötvös number is more frequently used in Europe, while Bond number is commonly used in other parts of the world. ==Definition== The Eötvös or Bond number is given by : * : difference in density of the two phases, (SI units: kg/m3) * ''g'': gravitational acceleration, (SI units : m/s2) * ''L'': characteristic length, (SI units : m) * : surface tension, (SI units : N/m) A high value of the Eötvös or Bond number indicates that the system is relatively unaffected by surface tension effects; a low value (typically less than one) indicates that surface tension dominates. Intermediate numbers indicate a non-trivial balance between the two effects. It may be derived in a number of ways, such as scaling the pressure of a drop of liquid on a solid surface. It is usually important, however, to find the right length scale specific to a problem by doing a ground-up scale analysis. Other similar dimensionless numbers are: : where Go and De are the Goucher and Deryagin numbers, which are identical: the Goucher number arises in wire coating problems and hence uses a radius as a typical length scale while the Deryagin number arises in plate film thickness problems and hence uses a Cartesian length. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Eötvös number」の詳細全文を読む スポンサード リンク
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