Skip to content
Snippets Groups Projects
shearflow.py 7.4 KiB
Newer Older
# Hedge - the Hybrid'n'Easy DG Environment
# Copyright (C) 2008 Andreas Kloeckner
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.




from __future__ import division
Andreas Klöckner's avatar
Andreas Klöckner committed
from __future__ import absolute_import
from __future__ import print_function
import numpy
import numpy.linalg as la




class SteadyShearFlow:
    def __init__(self):
        self.gamma = 1.5
        self.mu = 0.01
        self.prandtl = 0.72
        self.spec_gas_const = 287.1

    def __call__(self, t, x_vec):
        # JSH/TW Nodal DG Methods, p.326

        rho = numpy.ones_like(x_vec[0])
        rho_u = x_vec[1] * x_vec[1]
        rho_v = numpy.zeros_like(x_vec[0])
        e = (2 * self.mu * x_vec[0] + 10) / (self.gamma - 1) + x_vec[1]**4 / 2

        from hedge.tools import join_fields
        return join_fields(rho, e, rho_u, rho_v)

    def properties(self):
        return(self.gamma, self.mu, self.prandtl, self.spec_gas_const)

    def volume_interpolant(self, t, discr):
        return discr.convert_volume(
                        self(t, discr.nodes.T
                            .astype(discr.default_scalar_type)),
                        kind=discr.compute_kind)

    def boundary_interpolant(self, t, discr, tag):
        result = discr.convert_boundary(
                        self(t, discr.get_boundary(tag).nodes.T
                            .astype(discr.default_scalar_type)),
                        tag=tag, kind=discr.compute_kind)
        return result




def main():
    from hedge.backends import guess_run_context
    rcon = guess_run_context(
    #["cuda"]
    )

    from hedge.tools import EOCRecorder, to_obj_array
    eoc_rec = EOCRecorder()

    def boundary_tagger(vertices, el, face_nr, all_v):
        return ["inflow"]

    if rcon.is_head_rank:
        from hedge.mesh import make_rect_mesh, \
                               make_centered_regular_rect_mesh
        #mesh = make_rect_mesh((0,0), (10,1), max_area=0.01)
        refine = 1
        mesh = make_centered_regular_rect_mesh((0,0), (10,1), n=(20,4),
                            #periodicity=(True, False),
                            post_refine_factor=refine,
                            boundary_tagger=boundary_tagger)
        mesh_data = rcon.distribute_mesh(mesh)
    else:
        mesh_data = rcon.receive_mesh()

    for order in [3]:
        discr = rcon.make_discretization(mesh_data, order=order,
                        default_scalar_type=numpy.float64)

        from hedge.visualization import SiloVisualizer, VtkVisualizer
        #vis = VtkVisualizer(discr, rcon, "shearflow-%d" % order)
        vis = SiloVisualizer(discr, rcon)

        shearflow = SteadyShearFlow()
        fields = shearflow.volume_interpolant(0, discr)
        gamma, mu, prandtl, spec_gas_const = shearflow.properties()

        from hedge.models.gas_dynamics import GasDynamicsOperator
        op = GasDynamicsOperator(dimensions=2, gamma=gamma, mu=mu,
                prandtl=prandtl, spec_gas_const=spec_gas_const,
                bc_inflow=shearflow, bc_outflow=shearflow, bc_noslip=shearflow,
                inflow_tag="inflow", outflow_tag="outflow", noslip_tag="noslip")

        navierstokes_ex = op.bind(discr)

        max_eigval = [0]
        def rhs(t, q):
            ode_rhs, speed = navierstokes_ex(t, q)
            max_eigval[0] = speed
            return ode_rhs

        # needed to get first estimate of maximum eigenvalue
        rhs(0, fields)

        if rcon.is_head_rank:
Andreas Klöckner's avatar
Andreas Klöckner committed
            print("---------------------------------------------")
            print("order %d" % order)
            print("---------------------------------------------")
            print("#elements=", len(mesh.elements))

        from hedge.timestep import RK4TimeStepper
        stepper = RK4TimeStepper()

        # diagnostics setup ---------------------------------------------------
        from pytools.log import LogManager, add_general_quantities, \
                add_simulation_quantities, add_run_info

        logmgr = LogManager("navierstokes-cpu-%d-%d.dat" % (order, refine),
                            "w", rcon.communicator)
        add_run_info(logmgr)
        add_general_quantities(logmgr)
        add_simulation_quantities(logmgr)
        discr.add_instrumentation(logmgr)
        stepper.add_instrumentation(logmgr)

        logmgr.add_watches(["step.max", "t_sim.max", "t_step.max"])

        # timestep loop -------------------------------------------------------
        try:
            from hedge.timestep import times_and_steps
            step_it = times_and_steps(
                    final_time=0.3,
                    #max_steps=500,
                    logmgr=logmgr,
                    max_dt_getter=lambda t: op.estimate_timestep(discr,
                        stepper=stepper, t=t, max_eigenvalue=max_eigval[0]))

            for step, t, dt in step_it:
                if step % 10 == 0:
                #if False:
                    visf = vis.make_file("shearflow-%d-%04d" % (order, step))

                    #true_fields = shearflow.volume_interpolant(t, discr)

                    from pyvisfile.silo import DB_VARTYPE_VECTOR
                    vis.add_data(visf,
                            [
                                ("rho", discr.convert_volume(op.rho(fields), kind="numpy")),
                                ("e", discr.convert_volume(op.e(fields), kind="numpy")),
                                ("rho_u", discr.convert_volume(op.rho_u(fields), kind="numpy")),
                                ("u", discr.convert_volume(op.u(fields), kind="numpy")),

                                #("true_rho", discr.convert_volume(op.rho(true_fields), kind="numpy")),
                                #("true_e", discr.convert_volume(op.e(true_fields), kind="numpy")),
                                #("true_rho_u", discr.convert_volume(op.rho_u(true_fields), kind="numpy")),
                                #("true_u", discr.convert_volume(op.u(true_fields), kind="numpy")),
                                ],
                            expressions=[
                                #("diff_rho", "rho-true_rho"),
                                #("diff_e", "e-true_e"),
                                #("diff_rho_u", "rho_u-true_rho_u", DB_VARTYPE_VECTOR),

                                ("p", "0.4*(e- 0.5*(rho_u*u))"),
                                ],
                            time=t, step=step
                            )
                    visf.close()

                fields = stepper(fields, t, dt, rhs)

            true_fields = shearflow.volume_interpolant(t, discr)
            l2_error = discr.norm(op.u(fields)-op.u(true_fields))
            eoc_rec.add_data_point(order, l2_error)
Andreas Klöckner's avatar
Andreas Klöckner committed
            print()
            print(eoc_rec.pretty_print("P.Deg.", "L2 Error"))

            logmgr.set_constant("l2_error", l2_error)

        finally:
            vis.close()
            logmgr.save()
            discr.close()

if __name__ == "__main__":
    main()