Example #1
0
def test_lump_rhs(actx_factory, dim, order):
    """Test the inviscid rhs using the non-trivial mass lump case.

    The case is tested against the analytic expressions of the RHS.
    Checks several different orders and refinement levels to check error behavior.
    """
    actx = actx_factory()

    tolerance = 1e-10
    maxxerr = 0.0

    from pytools.convergence import EOCRecorder

    eoc_rec = EOCRecorder()

    for nel_1d in [4, 8, 12]:
        from meshmode.mesh.generation import (
            generate_regular_rect_mesh, )

        mesh = generate_regular_rect_mesh(
            a=(-5, ) * dim,
            b=(5, ) * dim,
            nelements_per_axis=(nel_1d, ) * dim,
        )

        logger.info(f"Number of elements: {mesh.nelements}")

        discr = EagerDGDiscretization(actx, mesh, order=order)
        nodes = thaw(actx, discr.nodes())

        # Init soln with Lump and expected RHS = 0
        center = np.zeros(shape=(dim, ))
        velocity = np.zeros(shape=(dim, ))
        lump = Lump(dim=dim, center=center, velocity=velocity)
        lump_soln = lump(nodes)
        boundaries = {
            BTAG_ALL: PrescribedInviscidBoundary(fluid_solution_func=lump)
        }
        inviscid_rhs = euler_operator(discr,
                                      eos=IdealSingleGas(),
                                      boundaries=boundaries,
                                      cv=lump_soln,
                                      time=0.0)
        expected_rhs = lump.exact_rhs(discr, cv=lump_soln, time=0)

        err_max = discr.norm((inviscid_rhs - expected_rhs).join(), np.inf)
        if err_max > maxxerr:
            maxxerr = err_max

        eoc_rec.add_data_point(1.0 / nel_1d, err_max)
    logger.info(f"Max error: {maxxerr}")

    logger.info(f"Error for (dim,order) = ({dim},{order}):\n" f"{eoc_rec}")

    assert (eoc_rec.order_estimate() >= order - 0.5
            or eoc_rec.max_error() < tolerance)
Example #2
0
def test_lump_rhs(actx_factory, dim, order, use_overintegration):
    """Test the inviscid rhs using the non-trivial mass lump case.

    The case is tested against the analytic expressions of the RHS.
    Checks several different orders and refinement levels to check error behavior.
    """
    actx = actx_factory()

    tolerance = 1e-10
    maxxerr = 0.0

    from pytools.convergence import EOCRecorder

    eoc_rec = EOCRecorder()

    for nel_1d in [4, 8, 12]:
        from meshmode.mesh.generation import (
            generate_regular_rect_mesh,
        )

        mesh = generate_regular_rect_mesh(
            a=(-5,) * dim, b=(5,) * dim, nelements_per_axis=(nel_1d,) * dim,
        )

        logger.info(f"Number of elements: {mesh.nelements}")

        from grudge.dof_desc import DISCR_TAG_BASE, DISCR_TAG_QUAD
        from meshmode.discretization.poly_element import \
            default_simplex_group_factory, QuadratureSimplexGroupFactory

        discr = EagerDGDiscretization(
            actx, mesh,
            discr_tag_to_group_factory={
                DISCR_TAG_BASE: default_simplex_group_factory(
                    base_dim=dim, order=order),
                DISCR_TAG_QUAD: QuadratureSimplexGroupFactory(2*order + 1)
            }
        )

        if use_overintegration:
            quadrature_tag = DISCR_TAG_QUAD
        else:
            quadrature_tag = None

        nodes = thaw(discr.nodes(), actx)

        # Init soln with Lump and expected RHS = 0
        center = np.zeros(shape=(dim,))
        velocity = np.zeros(shape=(dim,))
        lump = Lump(dim=dim, center=center, velocity=velocity)
        lump_soln = lump(nodes)
        gas_model = GasModel(eos=IdealSingleGas())
        fluid_state = make_fluid_state(lump_soln, gas_model)

        def _lump_boundary(discr, btag, gas_model, state_minus, **kwargs):
            actx = state_minus.array_context
            bnd_discr = discr.discr_from_dd(btag)
            nodes = thaw(bnd_discr.nodes(), actx)
            return make_fluid_state(lump(x_vec=nodes, cv=state_minus, **kwargs),
                                    gas_model)

        boundaries = {
            BTAG_ALL: PrescribedFluidBoundary(boundary_state_func=_lump_boundary)
        }

        inviscid_rhs = euler_operator(
            discr, state=fluid_state, gas_model=gas_model, boundaries=boundaries,
            time=0.0, quadrature_tag=quadrature_tag
        )
        expected_rhs = lump.exact_rhs(discr, cv=lump_soln, time=0)

        err_max = max_component_norm(discr, inviscid_rhs-expected_rhs, np.inf)
        if err_max > maxxerr:
            maxxerr = err_max

        eoc_rec.add_data_point(1.0 / nel_1d, err_max)
    logger.info(f"Max error: {maxxerr}")

    logger.info(
        f"Error for (dim,order) = ({dim},{order}):\n"
        f"{eoc_rec}"
    )

    assert (
        eoc_rec.order_estimate() >= order - 0.5
        or eoc_rec.max_error() < tolerance
    )