Navier–Stokes Equation
Simulate a fluid flow over a backward-facing step with the Navier–Stokes equation
Here 
is the vector-valued velocity field, 
is the pressure and 
the identity matrix. 
and 
are the density and viscosity, respectively.
Specify a region that models the backward-facing step.
Visualize the region with an inflow profile.
Specify an inflow profile boundary condition on the left edge.
Specify an outflow boundary condition by setting up a pressure value on the right.
Specify no-slip boundary conditions on the remaining walls.
Group the boundary conditions.
Set up the viscous Navier–Stokes equation.
Replace the density 
and the viscosity 
with material parameters and solve the equation on a mesh with specified spacing while interpolating the velocities 
and 
with second order and the pressure 
with first order.
Visualize the resulting velocity field and note the recirculation area behind the step.
Visualize an averaged velocity field as a density plot.
Visualize the resulting pressure distribution.
More details about this model can be found in the documentation.
