Stuart number
{{Short description|Dimensionless parameter in fluid mechanics}}
The Stuart number (N), also known as magnetic interaction parameter, is a dimensionless number of fluids, i.e. gases or liquids. It is named after mathematician John Trevor Stuart.{{Cite book |last=Massey |first=Bernard Stanford |url=https://www.google.fr/books/edition/Measures_in_Science_and_Engineering/ebEeAQAAIAAJ?hl=en&gbpv=0&bsq=Measures%20in%20science%20and%20engineering%20:%20their%20expression,%20relation,%20and%20interpretation%20by%20Massey,%20B.%20S.%20(Bernard%20Stanford) |title=Measures in Science and Engineering: Their Expression, Relation, and Interpretation |date=1986 |publisher=E. Horwood |isbn=978-0-470-20331-6 |language=en}}
It is defined as the ratio of electromagnetic to inertial forces, which gives an estimate of the relative importance of a magnetic field on a flow. The Stuart number is relevant for flows of conducting fluids, e.g. in fusion reactors, steel casters or plasmas.{{citation|surname1=D. Lee|surname2=H. Choi|periodical=Journal of Fluid Mechanics|title=Magnetohydrodynamic turbulent flow in a channel at low magnetic Reynolds number |volume=439|pages=367–394|date= 2001|issue=1|doi=10.1017/S0022112001004621|bibcode=2001JFM...439..367L|s2cid=121865399}}
Definition
:
- B – magnetic field
- Lc – characteristic length
- σ – electric conductivity
- U – characteristic velocity scale
- ρ – density
- Ha – Hartmann number
- Re – Reynolds number
References
{{Reflist}}
Further reading
- R. Moreau: Magnetohydrodynamics (= Fluid Mechanics and its Applications. Vol. 3). Kluwer Academic Publishers, Dordrecht u. a. 1990, {{ISBN|0-7923-0937-5}}, S. 127.
- P. A. Davidson: An Introduction to Magnetohydrodynamics. Cambridge University Press, Cambridge 2001, {{ISBN|0-521-79149-9}}, S. 97.
{{NonDimFluMech}}