Convection current

A convection current is a current that carries another quantity-like quantity with it. As a rule, the convection flow is a material flow , i.e. matter that transports further ( scalar or vectorial ) quantities.

It can be matter that is carried along by matter, such as the convection of solid particles by a flowing fluid , but also thermal energy or electrical charge that is set in motion by currents. In application areas of fluid dynamics , such as meteorology or mixing in process engineering, these processes are closely linked. The thermodynamics noted especially the heat transfer by convection .

In the theory of electricity , electrical charge, which is transported by charge carriers such as electrons or ions , forms a convection current in contrast to the displacement current without the movement of matter. In the older literature, a convection current without conduction losses (e.g. when static electricity moves on a rotating disk) is distinguished from conduction current, which has to overcome an ohmic resistance . Today this distinction is often no longer made.

In contrast, the Karlsruhe physics course also uses the distinction between conduction current (or conductive current) and entropy flow (or convective current) for entropy and momentum currents.

See also

• Jacket convection

literature

• Hans Dieter Baehr, Karl Stephan : Heat and mass transfer , Springer, Berlin 2003, pp. 87–89. ISBN 978-3-662-49676-3 .
• Ralf Weinekötter, Hermann Gericke: Mixing of solids , Springer, Berlin 1995, p. 4. ISBN 3-540-58567-2 .

Individual evidence

1. ↑ A. Eichenwald: Lectures on electricity , Springer, Berlin 1928, p. 101.
2. ^ As in: Wilfried Weißgerber: Electrical engineering for engineers - collection of formulas, Springer, Wiesbaden 2004, p. 1. ISBN 978-3-322-92821-4
3. ↑ Peter Schmälzle: Conductive and convective currents , in: Praxis der Naturwissenschaften. Physics in School : Everything Flows , 61: 2012, no. 1, p. 13f.