Sekundärströme

Sekundärströme, also known as secondary currents, are a phenomenon observed in various physical contexts, most notably in electromagnetism and fluid dynamics. In the realm of electromagnetism, secondary currents refer to induced currents that flow within a conductor when it is subjected to a changing magnetic field. These currents are a consequence of Faraday's law of induction. When a conductor is exposed to a varying magnetic flux, an electromotive force (EMF) is generated, which in turn drives currents within the conductor. These induced currents are often undesirable as they can lead to energy dissipation in the form of heat, a phenomenon known as Joule heating, and can also reduce the efficiency of electrical devices. Examples include eddy currents in transformer cores or induction heating.

In fluid dynamics, secondary currents manifest as cross-flows that exist in addition to the main flow, particularly in curved or non-uniform channels. These currents arise due to the interplay of inertial forces and pressure gradients. For instance, in a curved pipe, the fluid layers near the outer bend experience greater centrifugal forces than those near the inner bend. This leads to a pressure gradient that drives a secondary flow from the outer bend towards the inner bend in the core of the flow, and a return flow near the walls. These secondary currents can significantly influence mixing, transport phenomena, and the overall flow behavior. Understanding and predicting secondary currents is crucial in fields like hydraulics, aerodynamics, and chemical engineering.