Magnetohydrodynamics (MHD) is the branch of physics that studies the behavior of electrically conducting fluids—such as plasmas, liquid metals, and saltwater—in the presence of magnetic and electric fields. It combines principles from both fluid dynamics and electromagnetism.
In MHD, the motion of the fluid generates electric currents, which in turn interact with magnetic fields, producing Lorentz forces that affect the fluid’s motion. This creates a complex feedback loop between the fluid flow and electromagnetic fields. The resulting behavior is often highly dynamic and non-linear.
MHD is crucial in understanding and designing systems such as:
- Astrophysical phenomena (like solar flares and the behavior of the sun’s corona),
- Fusion reactors (such as tokamaks, where plasma confinement depends on magnetic fields),
- MHD generators and pumps (used for contactless flow control of liquid metals),
- Space weather and the interaction of solar wind with planetary magnetic fields.
By linking electromagnetism with fluid motion, MHD provides powerful tools for analyzing complex natural and engineered systems involving charged fluids.