Merge branch 'production' into production-pilot

.rtd-env-py3.yml

@@ -11,6 +11,7 @@ dependencies:
 - islpy
 - pip
 - pyopencl
+- scipy
 - pip:
   - "git+https://github.com/inducer/pymbolic.git#egg=pymbolic"
   - "git+https://github.com/inducer/loopy.git#egg=loopy"

doc/discretization.rst

@@ -29,6 +29,7 @@ discussion.  The following references are useful:
 * Shock handling [Woodward_1984]_
 * Artificial viscosity [Persson_2012]_
 * Boundary Condtitions [Mengaldo_2014]_, and [Poinsot_1992]_
+* Phenolics modeling [Lachaud_2014]_
 
 *MIRGE-Com* currently employs a strategy akin to the BR1 algorithm outlined in
 [Bassi_1997]_, but with thermal terms and chemical reaction sources as outlined in

doc/misc.rst

@@ -86,3 +86,5 @@ References
     `(DOI) <https://doi.org/10.1002/0471461296>`__
 .. [Giles_1988] Michael Giles (1988), Non-Reflecting Boundary Conditions for the Euler \
     Equations, CFDL-TR-88-1
+.. [Lachaud_2014] Jean Lachaud and Nagi Mansour (2014), Porous-Material Analysis Toolbox Based
+    on OpenFOAM and Applications, Journal of Thermophysics and Heat Transfer 28 2 

doc/operators/composite_materials.rst

@@ -0,0 +1,195 @@
+Wall Degradation Modeling
+=========================
+
+Conserved Quantities
+^^^^^^^^^^^^^^^^^^^^
+.. autoclass:: mirgecom.wall_model.PorousFlowDependentVars
+
+Equations of State
+^^^^^^^^^^^^^^^^^^
+.. autoclass:: mirgecom.wall_model.WallEOS
+.. autoclass:: mirgecom.wall_model.WallDependentVars
+
+Model-specific properties
+^^^^^^^^^^^^^^^^^^^^^^^^^
+    The properties of the materials are defined in specific files. These files
+    are required by :class:`~mirgecom.wall_model.WallEOS`.
+
+Carbon fiber
+------------
+.. automodule:: mirgecom.materials.carbon_fiber
+
+TACOT
+-----
+.. automodule:: mirgecom.materials.tacot
+
+Carbon Fiber Oxidation 
+^^^^^^^^^^^^^^^^^^^^^^
+
+    This section covers the response of carbon fiber when exposed to oxygen.
+    The carbon fibers are characterized as a highly porous material,
+    with void fraction $\approx 90\%$. As the material is exposed to the flow,
+    oxygen can diffuse inside the wall and result in oxidation, not only
+    limited to the surface but also as a volumetric process. For now, convection
+    inside the wall will be neglected and the species are only allowed to diffuse.
+
+    The temporal evolution of mass density is solved in
+    order to predict the material degradation. As the
+    :class:`~mirgecom.materials.carbon_fiber.Oxidation` progresses,
+    the temporal evolution of the fibers mass is given by
+
+    .. math ::
+        \frac{\partial \rho_s}{\partial t} = \dot{\omega_s} \mbox{ .}
+
+    This process creates gaseous species following
+
+    .. math ::
+        \frac{\partial \rho_g}{\partial t} = - \dot{\omega}_s \mbox{ ,}
+
+    where the
+    :attr:`~mirgecom.fluid.ConservedVars.mass`
+    is $\rho_g$. The source term indicates that the fibers become gas in order
+    to satisfy mass conservation.
+
+    The
+    :attr:`~mirgecom.fluid.ConservedVars.energy`
+    of the bulk material is given by
+
+    .. math::
+        \frac{\partial \rho_b e_b}{\partial t}
+        = \nabla \cdot \left( \bar{\boldsymbol{\kappa}} \nabla T 
+        + h_\alpha \mathbf{J}_{\alpha} \right)
+        \mbox{ .}
+
+    The first term on the RHS is modeled as an effective diffusive transfer
+    using Fourier's law, where the thermal conductivity is given by
+    $\bar{\boldsymbol{\kappa}}$.
+    The second term on the RHS is due to the species diffusion, where the
+    species specific enthalpy ${h}_{\alpha}$, and the species
+    diffusive flux vector $\mathbf{J}_{\alpha}$. The sub-index $b$ is the bulk
+    material consisting of both solid and gas phases, where
+
+    .. math::
+        \rho_b e_b = \epsilon_{g} \rho_g e_g + \epsilon_s \rho_s h_s \mbox{ .}
+
+    The internal energy of the gas is given by $e_g(T)$ and the solid 
+    energy/enthalpy is $h_s(T)$.
+
+    From the conserved variables, it is possible to compute the oxidation
+    progress, denoted by
+    :attr:`~mirgecom.wall_model.WallDependentVars.tau`.
+    As a consequence, the instantaneous material properties will change due to
+    the mass loss.
+
+    The
+    :attr:`~mirgecom.eos.GasDependentVars.temperature`
+    is evaluated using Newton iteration based on both
+    :attr:`~mirgecom.eos.PyrometheusMixture.get_internal_energy` and
+    :attr:`~mirgecom.wall_model.WallEOS.enthalpy`,
+    as well as their respective derivatives, namely
+    :attr:`~mirgecom.eos.PyrometheusMixture.heat_capacity_cv` and
+    :attr:`~mirgecom.wall_model.WallEOS.heat_capacity`.
+    Note that :mod:`pyrometheus` is used to handle the species properties.
+
+Composite Materials
+^^^^^^^^^^^^^^^^^^^
+
+    This section covers the response of composite materials made of phenolic
+    resin and carbon fibers.
+    The carbon fibers are characterized as a highly porous material,
+    with void fraction $\approx 90\%$. Phenolic resins are added to rigidize
+    the fibers by permeating the material and filling partially the gaps between
+    fibers. As the material is heated up by the flow, the resin pyrolysis, i.e.,
+    it degrades and produces gaseous species.
+
+    The temporal evolution of wall density is solved in
+    order to predict the material degradation. As the
+    :class:`~mirgecom.materials.tacot.Pyrolysis` progresses, the mass of each 
+    $i$ constituents of the resin, denoted by
+    :attr:`~mirgecom.wall_model.PorousFlowDependentVars.material_densities`,
+    is calculated as
+
+    .. math ::
+        \frac{\partial \rho_i}{\partial t} = \dot{\omega}_i \mbox{ .}
+
+    This process creates gaseous species following
+
+    .. math ::
+        \frac{\partial \rho_g}{\partial t} + \nabla \cdot \rho_g \mathbf{u} = 
+            - \sum_i \dot{\omega}_i \mbox{ ,}
+
+    where the
+    :attr:`~mirgecom.fluid.ConservedVars.mass`
+    is $\rho_g$. The source term indicates that all solid resin must become
+    gas in order to satisfy mass conservation. Lastly, the gas velocity
+    $\mathbf{u}$ is obtained by Darcy's law, given by
+
+    .. math::
+        \mathbf{u} = \frac{\mathbf{K}}{\mu \epsilon} \cdot \nabla P \mbox{ .}
+
+    In this equation, $\mathbf{K}$ is the second-order permeability tensor,
+    $\mu$ is the gas viscosity, $\epsilon$ is the void fraction and $P$ is
+    the gas pressure.
+
+    The
+    :attr:`~mirgecom.fluid.ConservedVars.energy`
+    of the bulk material is given by
+
+    .. math::
+        \frac{\partial \rho_b e_b}{\partial t}
+        + \nabla \cdot (\epsilon_{g} \rho_g h_g \mathbf{u})
+        = \nabla \cdot \left( \bar{\boldsymbol{\kappa}} \nabla T \right)
+        + \mu \epsilon_{g}^2 (\bar{\mathbf{K}}^{-1} \cdot \vec{v} ) \cdot \vec{v}
+        \mbox{ .}
+
+    The first term on the RHS is modeled as an effective diffusive transfer
+    using Fourier's law, where the thermal conductivity is given by
+    $\bar{\boldsymbol{\kappa}}$. The second term on the RHS account for the
+    viscous dissipation in the Darcy's flow. The sub-index $b$ is the bulk
+    material consisting of both solid and gas phases, where
+
+    .. math::
+        \rho_b e_b = \epsilon_{g} \rho_g e_g + \epsilon_s \rho_s e_s \mbox{ .}
+
+    The energy of the gas is given by $e_g(T) = h_g(T) - \frac{P}{\rho_g}$,
+    where $h_g$ is its enthalpy.
+
+    From the conserved variables, it is possible to compute the decomposition
+    status, denoted by
+    :attr:`~mirgecom.wall_model.WallDependentVars.tau`.
+    This yields the proportion of virgin (unpyrolyzed material) to char (fully
+    pyrolyzed) and, consequently, the different thermophysicochemical
+    properties of the solid phase. Thus, the instantaneous material properties
+    depend on the current state of the material, as well as the 
+    :attr:`~mirgecom.eos.GasDependentVars.temperature`.
+    It is evaluated using Newton iteration based on both
+    :attr:`~mirgecom.materials.tacot.GasProperties.enthalpy` (tabulated
+    data) or 
+    :attr:`~mirgecom.eos.PyrometheusMixture.get_internal_energy` (Pyrometheus)
+    and
+    :attr:`~mirgecom.wall_model.WallEOS.enthalpy`,
+    as well as their respective derivatives, namely
+    :attr:`~mirgecom.materials.tacot.GasProperties.heat_capacity` and
+    :attr:`~mirgecom.wall_model.WallEOS.heat_capacity`.
+
+    In *MIRGE-Com*, the solid properties are obtained by fitting polynomials
+    to tabulated data for easy evaluation of the properties based on the
+    temperature. The complete list of properties can be find, for instance, in
+    :mod:`~mirgecom.materials.tacot`.
+    Different materials can be incorporated as separated files.
+
+    The
+    :class:`~mirgecom.materials.tacot.GasProperties` are obtained based on
+    tabulated data, assuming chemical equilibrium, and evaluated with splines
+    for interpolation of the entries. However, the data is currently obtained
+    by PICA.
+
+.. important ::
+
+    The current implementation follows the description of [Lachaud_2014]_ 
+    for type 2 code. Additional details, extensive formulation and references
+    are provided in https://github.com/illinois-ceesd/phenolics-notes
+
+Helper Functions
+----------------
+.. autofunction:: mirgecom.multiphysics.phenolics.initializer

doc/operators/operators.rst

@@ -9,3 +9,4 @@ Operators
    artificial_viscosity
    gas-dynamics
    thermally_coupled
+   composite_materials

examples/ablation-workshop-mpi-lazy.py

@@ -0,0 +1 @@
+ablation-workshop-mpi.py