Transport theorem

The Transport Theorem, also known as the Transport Equation or the Lagrangian Transport Theorem, is a fundamental concept in the fields of mathematical physics and fluid dynamics. It deals with the transport of quantities (such as mass, energy, or momentum) within a moving fluid or along a flow field. In its simplest form, the theorem describes how a quantity changes as it is transported by a flow. This can be expressed in both Lagrangian and Eulerian frameworks.