incompressible.problems package¶
Submodules¶
incompressible.problems.converge module¶
Initialize a smooth incompressible convergence test. Here, the velocities are initialized as
\[ \begin{align}\begin{aligned}u(x,y) = 1 - 2 \cos(2 \pi x) \sin(2 \pi y)\\v(x,y) = 1 + 2 \sin(2 \pi x) \cos(2 \pi y)\end{aligned}\end{align} \]
and the exact solution at some later time t is then
\[ \begin{align}\begin{aligned}u(x,y,t) = 1 - 2 \cos(2 \pi (x - t)) \sin(2 \pi (y - t))\\v(x,y,t) = 1 + 2 \sin(2 \pi (x - t)) \cos(2 \pi (y - t))\\p(x,y,t) = -\cos(4 \pi (x - t)) - \cos(4 \pi (y - t))\end{aligned}\end{align} \]
The numerical solution can be compared to the exact solution to measure the convergence rate of the algorithm.
incompressible.problems.shear module¶
Initialize the doubly periodic shear layer (see, for example, Martin and Colella, 2000, JCP, 163, 271). This is run in a unit square domain, with periodic boundary conditions on all sides. Here, the initial velocity is:
/ tanh(rho_s (y-0.25)) if y <= 0.5
u(x,y,t=0) = <
\ tanh(rho_s (0.75-y)) if y > 0.5
v(x,y,t=0) = delta_s sin(2 pi x)