capytaine.bem.solver module

Solver for the BEM problem.

problem = RadiationProblem(...)
result = BEMSolver(green_functions=..., engine=...).solve(problem)
class capytaine.bem.solver.BEMSolver(*, green_function=None, engine=None)[source]

Bases: object

Solver for linear potential flow problems.

Parameters:

  • green_function (AbstractGreenFunction, optional) – Object handling the computation of the Green function. (default: Delhommeau)

  • engine (MatrixEngine, optional) – Object handling the building of matrices and the resolution of linear systems with these matrices. (default: BasicMatrixEngine)

Variables:

exportable_settings (dict) – Settings of the solver that can be saved to reinit the same solver later.

compute_free_surface_elevation(points, result)[source]

Compute the value of the free surface elevation at given points for a previously solved potential flow problem.

Parameters:

  • points (array of shape (2,) or (N, 2), or 2-ple of arrays returned by meshgrid, or cpt.Mesh or cpt.CollectionOfMeshes object) – Coordinates of the point(s) at which the free surface elevation should be computed

  • result (LinearPotentialFlowResult) – The return of the BEM solver

Returns:

The value of the free surface elevation at the points

Return type:

complex-valued array of shape (1,) or (N,) or (nx, ny, nz) or (mesh.nb_faces,) depending of the kind of input

Raises:

Exception – if the LinearPotentialFlowResult object given as input does not contain the source distribution.:

compute_potential(points, result)[source]

Compute the value of the potential at given points for a previously solved potential flow problem.

Parameters:

  • points (array of shape (3,) or (N, 3), or 3-ple of arrays returned by meshgrid, or cpt.Mesh or cpt.CollectionOfMeshes object) – Coordinates of the point(s) at which the potential should be computed

  • result (LinearPotentialFlowResult) – The return of the BEM solver

Returns:

The value of the potential at the points

Return type:

complex-valued array of shape (1,) or (N,) or (nx, ny, nz) or (mesh.nb_faces,) depending of the kind of input

Raises:

Exception – if the LinearPotentialFlowResult object given as input does not contain the source distribution.:

compute_pressure(points, result)[source]

Compute the value of the pressure at given points for a previously solved potential flow problem.

Parameters:

  • points (array of shape (3,) or (N, 3), or 3-ple of arrays returned by meshgrid, or cpt.Mesh or cpt.CollectionOfMeshes object) – Coordinates of the point(s) at which the pressure should be computed

  • result (LinearPotentialFlowResult) – The return of the BEM solver

Returns:

The value of the pressure at the points

Return type:

complex-valued array of shape (1,) or (N,) or (nx, ny, nz) or (mesh.nb_faces,) depending of the kind of input

Raises:

Exception – if the LinearPotentialFlowResult object given as input does not contain the source distribution.:

compute_velocity(points, result)[source]

Compute the value of the velocity vector at given points for a previously solved potential flow problem.

Parameters:

  • points (array of shape (3,) or (N, 3), or 3-ple of arrays returned by meshgrid, or cpt.Mesh or cpt.CollectionOfMeshes object) – Coordinates of the point(s) at which the velocity should be computed

  • result (LinearPotentialFlowResult) – The return of the BEM solver

Returns:

The value of the velocity at the points

Return type:

complex-valued array of shape (3,) or (N,, 3) or (nx, ny, nz, 3) or (mesh.nb_faces, 3) depending of the kind of input

Raises:

Exception – if the LinearPotentialFlowResult object given as input does not contain the source distribution.:

fill_dataset(dataset, bodies, *, method='indirect', n_jobs=1, _check_wavelength=True, **kwargs)[source]

Solve a set of problems defined by the coordinates of an xarray dataset.

Parameters:

  • dataset (xarray Dataset) – dataset containing the problems parameters: frequency, radiating_dof, water_depth, …

  • bodies (FloatingBody or list of FloatingBody) – The body or bodies involved in the problems They should all have different names.

  • method (string, optional) – select boundary integral approach indirect (i.e.Nemoh)/direct (i.e.WAMIT) (default: indirect)

  • n_jobs (int, optional (default: 1)) – the number of jobs to run in parallel using the optional dependency joblib By defaults: do not use joblib and solve sequentially.

  • progress_bar (bool, optional (default: True)) – Display a progress bar while solving

  • _check_wavelength (bool, optional (default: True)) – If True, the frequencies are compared to the mesh resolution and the estimated first irregular frequency to warn the user.

Return type:

xarray Dataset

classmethod from_exported_settings()[source]
get_free_surface_elevation(result, free_surface, keep_details=False)[source]

Compute the elevation of the free surface on a mesh for a previously solved problem.

The newer method compute_free_surface_elevation should be preferred in the future.

Parameters:

  • result (LinearPotentialFlowResult) – the return of the solver

  • free_surface (FreeSurface) – a meshed free surface

  • keep_details (bool, optional) – if True, keep the free surface elevation in the LinearPotentialFlowResult (default:False)

Returns:

the free surface elevation on each faces of the meshed free surface

Return type:

array of shape (free_surface.nb_faces,)

Raises:

Exception – if the Result object given as input does not contain the source distribution.:

get_potential_on_mesh(result, mesh, chunk_size=50)[source]

Compute the potential on a mesh for the potential field of a previously solved problem. Since the interaction matrix does not need to be computed in full to compute the matrix-vector product, only a few lines are evaluated at a time to reduce the memory cost of the operation.

The newer method compute_potential should be preferred in the future.

Parameters:

  • result (LinearPotentialFlowResult) – the return of the BEM solver

  • mesh (Mesh or CollectionOfMeshes) – a mesh

  • chunk_size (int, optional) – Number of lines to compute in the matrix. (legacy, should be passed as an engine setting instead).

Returns:

potential on the faces of the mesh

Return type:

array of shape (mesh.nb_faces,)

Raises:

Exception – if the Result object given as input does not contain the source distribution.:

solve(problem, method='indirect', keep_details=True, _check_wavelength=True)[source]

Solve the linear potential flow problem.

Parameters:

  • problem (LinearPotentialFlowProblem) – the problem to be solved

  • method (string, optional) – select boundary integral approach indirect (i.e.Nemoh)/direct (i.e.WAMIT) (default: indirect)

  • keep_details (bool, optional) – if True, store the sources and the potential on the floating body in the output object (default: True)

  • _check_wavelength (bool, optional (default: True)) – If True, the frequencies are compared to the mesh resolution and the estimated first irregular frequency to warn the user.

Returns:

an object storing the problem data and its results

Return type:

LinearPotentialFlowResult

solve_all(problems, *, method='indirect', n_jobs=1, progress_bar=True, _check_wavelength=True, **kwargs)[source]

Solve several problems. Optional keyword arguments are passed to BEMSolver.solve.

Parameters:

  • problems (list of LinearPotentialFlowProblem) – several problems to be solved

  • method (string, optional) – select boundary integral approach indirect (i.e.Nemoh)/direct (i.e.WAMIT) (default: indirect)

  • n_jobs (int, optional (default: 1)) – the number of jobs to run in parallel using the optional dependency joblib By defaults: do not use joblib and solve sequentially.

  • progress_bar (bool, optional (default: True)) – Display a progress bar while solving

  • _check_wavelength (bool, optional (default: True)) – If True, the frequencies are compared to the mesh resolution and the estimated first irregular frequency to warn the user.

Returns:

the solved problems

Return type:

list of LinearPotentialFlowResult