Unsteady
Unsteady is an adjective describing something that is not in a steady state; its properties vary with time. In scientific and engineering contexts, unsteady implies a time-dependent state, as opposed to steady or steady-state conditions where variables remain constant or evolve to a time-invariant regime.
In fluid dynamics, unsteady flow refers to a fluid motion whose velocity field depends on time. Unsteadiness
Mathematically, unsteady problems involve solving time-dependent equations, such as partial differential equations or ordinary differential equations,
Unsteadiness is common across disciplines. In mechanical and aerospace engineering, unsteady aerodynamics, transient combustion, and valve
Note that unsteady does not inherently imply instability; a system can be unsteady yet stable, with bounded