PR #538: from firedrakeproject/compressible_coriolis_change

Move omega from equations to parameters

examples/compressible/skamarock_klemp_hydrostatic.py

@@ -39,10 +39,9 @@
 domain = Domain(mesh, dt, "RTCF", 1)
 
 # Equation
-parameters = CompressibleParameters()
-Omega = as_vector((0., 0., 0.5e-4))
+parameters = CompressibleParameters(Omega=0.5e-4)
 balanced_pg = as_vector((0., -1.0e-4*20, 0.))
-eqns = CompressibleEulerEquations(domain, parameters, Omega=Omega,
+eqns = CompressibleEulerEquations(domain, parameters,
                                   extra_terms=[("u", balanced_pg)])
 
 # I/O

gusto/core/configuration.py

@@ -114,6 +114,7 @@ class BoussinesqParameters(Configuration):
     g = 9.810616
     N = 0.01  # Brunt-Vaisala frequency (1/s)
     cs = 340  # sound speed (for compressible case) (m/s)
+    Omega = None
 
 
 class CompressibleParameters(Configuration):
@@ -136,6 +137,7 @@ class CompressibleParameters(Configuration):
     w_sat2 = -17.27  # second const. in Teten's formula (no units)
     w_sat3 = 35.86  # third const. in Teten's formula (K)
     w_sat4 = 610.9  # fourth const. in Teten's formula (Pa)
+    Omega = None    # Rotation rate
 
 
 class ShallowWaterParameters(Configuration):

gusto/equations/boussinesq_equations.py

@@ -1,6 +1,6 @@
 """Defines the Boussinesq equations."""
 
-from firedrake import inner, dx, div, cross, split
+from firedrake import inner, dx, div, cross, split, as_vector
 from firedrake.fml import subject
 from gusto.core.labels import (
     time_derivative, transport, prognostic, linearisation,
@@ -40,7 +40,6 @@ class BoussinesqEquations(PrognosticEquationSet):
 
     def __init__(self, domain, parameters,
                  compressible=True,
-                 Omega=None,
                  space_names=None,
                  linearisation_map='default',
                  u_transport_option="vector_invariant_form",
@@ -54,8 +53,6 @@ def __init__(self, domain, parameters,
                 the model's physical parameters.
             compressible (bool, optional): flag to indicate whether the
                 equations are compressible. Defaults to True
-            Omega (:class:`ufl.Expr`, optional): an expression for the planet's
-                rotation vector. Defaults to None.
             space_names (dict, optional): a dictionary of strings for names of
                 the function spaces to use for the spatial discretisation. The
                 keys are the names of the prognostic variables. Defaults to None
@@ -191,11 +188,12 @@ def __init__(self, domain, parameters,
         # -------------------------------------------------------------------- #
         # Extra Terms (Coriolis)
         # -------------------------------------------------------------------- #
-        if Omega is not None:
+        if self.parameters.Omega is not None:
             # TODO: add linearisation
-            residual += coriolis(subject(prognostic(
+            Omega = as_vector((0, 0, self.parameters.Omega))
+            coriolis_form = coriolis(subject(prognostic(
                 inner(w, cross(2*Omega, u))*dx, 'u'), self.X))
-
+            residual += coriolis_form
         # -------------------------------------------------------------------- #
         # Linearise equations
         # -------------------------------------------------------------------- #
@@ -227,7 +225,6 @@ class LinearBoussinesqEquations(BoussinesqEquations):
 
     def __init__(self, domain, parameters,
                  compressible=True,
-                 Omega=None,
                  space_names=None,
                  linearisation_map='default',
                  u_transport_option="vector_invariant_form",
@@ -241,8 +238,6 @@ def __init__(self, domain, parameters,
                 the model's physical parameters.
             compressible (bool, optional): flag to indicate whether the
                 equations are compressible. Defaults to True
-            Omega (:class:`ufl.Expr`, optional): an expression for the planet's
-                rotation vector. Defaults to None.
             space_names (dict, optional): a dictionary of strings for names of
                 the function spaces to use for the spatial discretisation. The
                 keys are the names of the prognostic variables. Defaults to None
@@ -278,7 +273,6 @@ def __init__(self, domain, parameters,
         super().__init__(domain=domain,
                          parameters=parameters,
                          compressible=compressible,
-                         Omega=Omega,
                          space_names=space_names,
                          linearisation_map=linearisation_map,
                          u_transport_option=u_transport_option,

gusto/equations/compressible_euler_equations.py

@@ -2,7 +2,7 @@
 
 from firedrake import (
     sin, pi, inner, dx, div, cross, FunctionSpace, FacetNormal, jump, avg, dS_v,
-    conditional, SpatialCoordinate, split, Constant
+    conditional, SpatialCoordinate, split, Constant, as_vector
 )
 from firedrake.fml import subject, replace_subject
 from gusto.core.labels import (
@@ -34,7 +34,7 @@ class CompressibleEulerEquations(PrognosticEquationSet):
     pressure.
     """
 
-    def __init__(self, domain, parameters, Omega=None, sponge_options=None,
+    def __init__(self, domain, parameters, sponge_options=None,
                  extra_terms=None, space_names=None,
                  linearisation_map='default',
                  u_transport_option="vector_invariant_form",
@@ -47,8 +47,6 @@ def __init__(self, domain, parameters, Omega=None, sponge_options=None,
                 mesh and the compatible function spaces.
             parameters (:class:`Configuration`, optional): an object containing
                 the model's physical parameters.
-            Omega (:class:`ufl.Expr`, optional): an expression for the planet's
-                rotation vector. Defaults to None.
             sponge_options (:class:`SpongeLayerParameters`, optional): any
                 parameters for applying a sponge layer to the upper boundary.
                 Defaults to None.
@@ -216,10 +214,12 @@ def __init__(self, domain, parameters, Omega=None, sponge_options=None,
         # -------------------------------------------------------------------- #
         # Extra Terms (Coriolis, Sponge, Diffusion and others)
         # -------------------------------------------------------------------- #
-        if Omega is not None:
+        if parameters.Omega is not None:
             # TODO: add linearisation
-            residual += coriolis(subject(prognostic(
-                inner(w, cross(2*Omega, u))*dx, "u"), self.X))
+            Omega = as_vector((0, 0, parameters.Omega))
+            coriolis_form = coriolis(subject(prognostic(
+                inner(w, cross(2*Omega, u))*dx, 'u'), self.X))
+            residual += coriolis_form
 
         if sponge_options is not None:
             W_DG = FunctionSpace(domain.mesh, "DG", 2)
@@ -279,7 +279,7 @@ class HydrostaticCompressibleEulerEquations(CompressibleEulerEquations):
     equations.
     """
 
-    def __init__(self, domain, parameters, Omega=None, sponge=None,
+    def __init__(self, domain, parameters, sponge=None,
                  extra_terms=None, space_names=None, linearisation_map='default',
                  u_transport_option="vector_invariant_form",
                  diffusion_options=None,
@@ -291,8 +291,6 @@ def __init__(self, domain, parameters, Omega=None, sponge=None,
                 mesh and the compatible function spaces.
             parameters (:class:`Configuration`, optional): an object containing
                 the model's physical parameters.
-            Omega (:class:`ufl.Expr`, optional): an expression for the planet's
-                rotation vector. Defaults to None.
             sponge (:class:`ufl.Expr`, optional): an expression for a sponge
                 layer. Defaults to None.
             extra_terms (:class:`ufl.Expr`, optional): any extra terms to be
@@ -325,7 +323,7 @@ def __init__(self, domain, parameters, Omega=None, sponge=None,
             NotImplementedError: only mixing ratio tracers are implemented.
         """
 
-        super().__init__(domain, parameters, Omega=Omega, sponge=sponge,
+        super().__init__(domain, parameters, sponge=sponge,
                          extra_terms=extra_terms, space_names=space_names,
                          linearisation_map=linearisation_map,
                          u_transport_option=u_transport_option,