Navier–Stokes equations

These equations describe how a viscous fluid moves, balancing acceleration against advection, viscous diffusion and a kinematic pressure term, together with incompressibility. They are used throughout fluid dynamics to model flows in pipes, rivers, aircraft and weather.

\begin{aligned}\frac{\partial \vec u}{\partial t}+\vec u\cdot\nabla\vec u-\nu\nabla^2\vec u&=-\nabla h\\\nabla\cdot\vec u&=0\end{aligned}

What the symbols mean

flow velocity vector (m/s)
time (s)
kinematic viscosity (m^2/s)
kinematic pressure p/rho, pressure divided by density (m^2/s^2)
vector gradient operator
vector Laplacian operator
divergence operator

About this formula

  • FieldPhysics
  • TopicFluid dynamics
  • LevelAdvanced
  • Also calledNavier-Stokes equations, Navier-Stokes equation, incompressible fluid flow equations, viscous fluid motion equations, fluid momentum equation, incompressible Navier-Stokes
  • SourceWikidata Q201321

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