Solvers

Solvers

IncompressibleNavierStokes.get_cfl_timestep! Method

get_cfl_timestep!(buf, u, setup) -> Any

Get proposed maximum time step for convection and diffusion terms.

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IncompressibleNavierStokes.get_state Method

get_state(
    stepper
) -> NamedTuple{(:u, :temp, :t, :n), <:NTuple{4, Any}}

Get state (; u, temp, t, n) from stepper.

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IncompressibleNavierStokes.solve_unsteady Method

solve_unsteady(
;
    setup,
    tlims,
    ustart,
    tempstart,
    method,
    psolver,
    Δt,
    Δt_min,
    cfl,
    n_adapt_Δt,
    docopy,
    processors,
    θ,
    cache
)

Solve unsteady problem using method.

If Δt is a real number, it is rounded such that (t_end - t_start) / Δt is an integer. If Δt = nothing, the time step is chosen every n_adapt_Δt iteration with CFL-number cfl. If Δt_min is given, the adaptive time step never goes below it.

The processors are called after every time step.

Note that the state observable passed to the processor.initialize function contains vector living on the device, and you may have to move them back to the host using Array(u) in the processor.

Return (; u, t), outputs, where outputs is a named tuple with the outputs of processors with the same field names.

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Processors

Processors can be used to process the solution in solve_unsteady after every time step.

IncompressibleNavierStokes.fieldsaver Method

fieldsaver(; setup, nupdate)

Create processor that stores the solution and time every nupdate time step.

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IncompressibleNavierStokes.observefield Method

observefield(state; setup, fieldname, logtol, psolver)

Observe field fieldname at pressure points.

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IncompressibleNavierStokes.observespectrum Method

observespectrum(state; setup, npoint, a)

Observe energy spectrum of state.

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IncompressibleNavierStokes.processor Function

processor(
    initialize
) -> NamedTuple{(:initialize, :finalize), <:Tuple{Any, IncompressibleNavierStokes.var"#265#266"}}
processor(
    initialize,
    finalize
) -> NamedTuple{(:initialize, :finalize), <:Tuple{Any, Any}}

Process results from time stepping. Before time stepping, the initialize function is called on an observable of the time stepper state, returning initialized. The observable is updated every time step.

After timestepping, the finalize function is called on initialized and the final state.

See the following example:

function initialize(state)
    s = 0
    println("Let's sum up the time steps")
    on(state) do (; n, t)
        println("The summand is $n, the time is $t")
        s = s + n
    end
    s
end

finalize(i, state) = println("The final sum (at time t=$(state.t)) is $s")
p = processor(initialize, finalize)

When solved for 6 time steps from t=0 to t=2 the displayed output is

Let's sum up the time steps
The summand is 0, the time is 0.0
The summand is 1, the time is 0.4
The summand is 2, the time is 0.8
The summand is 3, the time is 1.2
The summand is 4, the time is 1.6
The summand is 5, the time is 2.0
The final sum (at time t=2.0) is 15

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IncompressibleNavierStokes.save_vtk Method

save_vtk(state; setup, filename, kwargs...)

Save fields to vtk file.

The kwargs are passed to snapshotsaver.

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IncompressibleNavierStokes.snapshotsaver Method

snapshotsaver(state; setup, fieldnames, psolver)

In the case of a 2D setup, the velocity field is saved as a 3D vector with a z-component of zero, as this seems to be preferred by ParaView.

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IncompressibleNavierStokes.timelogger Method

timelogger(
;
    showiter,
    showt,
    showdt,
    showmax,
    showspeed,
    nupdate
) -> @NamedTuple{initialize::IncompressibleNavierStokes.var"#268#270"{Bool, Bool, Bool, Bool, Bool, Int64}, finalize::IncompressibleNavierStokes.var"#265#266"}

Create processor that logs time step information.

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IncompressibleNavierStokes.vtk_writer Method

vtk_writer(; setup, nupdate, dir, filename, kwargs...)

Create processor that writes the solution every nupdate time steps to a VTK file. The resulting Paraview data collection file is stored in "$dir/$filename.pvd". The kwargs are passed to snapshotsaver.

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