Stuart number

The Stuart number  N (also English interaction parameter ) is a dimensionless number of fluids , i.e. gases or liquids .

It is defined as the ratio between electromagnetic and inertial forces , i.e. it gives an estimate of the relative influence of a magnetic field on a flow . Significantly, such a flow estimation for conducting fluids, such as in fusion reactors , during steel casting , or in plasmas .

definition

${\displaystyle {\it {N}}={\frac {Ha^{2}}{Re}}={\frac {B^{2}\cdot L_{c}\cdot \sigma }{\rho \cdot U}}}$

• ${\displaystyle Ha}$- Hartmann number
• ${\displaystyle Re}$- Reynolds number
• ${\displaystyle B}$- magnetic flux density
• ${\displaystyle L_{c}}$- characteristic length of the system
• ${\displaystyle \sigma }$- electrical conductivity
• ${\displaystyle \rho }$- density of the fluid
• ${\displaystyle U}$- flow velocity .

literature

• R. Moreau: Magnetohydrodynamics (= Fluid Mechanics and its Applications. Vol. 3). Kluwer Academic Publishers, Dordrecht et al. 1990, ISBN 0-7923-0937-5 , p. 127.
• PA Davidson: An Introduction to Magnetohydrodynamics. Cambridge University Press, Cambridge 2001, ISBN 0-521-791499 , p. 97.

Individual evidence

1. ↑ D. Lee, H. Choi,: Magnetohydrodynamic turbulent flow in a channel at low magnetic Reynolds number . In: Journal of Fluid Mechanics . tape 439 , 2001, p. 367-394 , doi : 10.1017 / S0022112001004621 .