flux
Flux
Table of Contents
1 flux
- flux
- quantity per unit time per unit area, quantity/(time*area)
- (no term)
- Quantities that can be fluxed in fluids include fluid mass, momentum, energy, etc.
There are three fundamental mechanisms of flux of interest in fluid mechanics:
- convective flux
- diffusive flux
- radiative flux
- the quantity is carried with the flow
- the quantity migrates from zones of high concentration to zones of low concentration by random molecular motion
- the quantity (e.g. heat) is carried by waves such as electromagnetic waves (in the infrared spectrum in the case of heat).
Flux examples:
- \( \rho \mathbf{v} \) : mass flux
- \( \rho u \mathbf{v} \):flux of x component of momentum
- \( \rho v \mathbf{v} \):flux of y component of momentum
- \( \rho e \mathbf{v} \):flux of internal energy
- \( \rho (e+\frac{v^2}{2}) \mathbf{v} \):flux of total energy
- diffusion flux= total flux - convective flux
1.1 flux vs vector
- The flux of a vector is a matrix
- The flux of a scalar is a vector
