From 52160fcc241f9df85d7fabc6775e9c49e0229a26 Mon Sep 17 00:00:00 2001
From: Alexandru Fikl <alexfikl@gmail.com>
Date: Tue, 25 Aug 2020 19:35:08 -0500
Subject: [PATCH] update SurfaceAdvectionOperator
---
grudge/models/advection.py | 22 +++-------------------
grudge/symbolic/primitives.py | 4 ----
2 files changed, 3 insertions(+), 23 deletions(-)
diff --git a/grudge/models/advection.py b/grudge/models/advection.py
index 659c10f8..b752a0dc 100644
--- a/grudge/models/advection.py
+++ b/grudge/models/advection.py
@@ -199,7 +199,9 @@ def v_dot_n_tpair(velocity, dd=None):
def surface_advection_weak_flux(flux_type, u, velocity):
v_dot_n = v_dot_n_tpair(velocity, dd=u.dd)
- v_dot_n = sym.cse(0.5 * v_dot_n.jump, "v_dot_normal")
+ # NOTE: the normals in v_dot_n point to the exterior of their respective
+ # elements, so this is actually just an average
+ v_dot_n = sym.cse(0.5 * (v_dot_n.int - v_dot_n.ext), "v_dot_normal")
flux_type = flux_type.lower()
if flux_type == "central":
@@ -210,16 +212,6 @@ def surface_advection_weak_flux(flux_type, u, velocity):
raise ValueError("flux `{}` is not implemented".format(flux_type))
-def surface_penalty_flux(u, velocity, tau=1.0):
- if abs(tau) < 1.0e-14:
- return 0.0
-
- v_dot_n = v_dot_n_tpair(velocity, dd=u.dd)
- return sym.If(sym.Comparison(v_dot_n.avg, ">", 0),
- 0.5 * tau * u.avg * v_dot_n.int,
- 0.0)
-
-
class SurfaceAdvectionOperator(AdvectionOperatorBase):
def __init__(self, v, flux_type="central", quad_tag=None):
super(SurfaceAdvectionOperator, self).__init__(
@@ -230,19 +222,12 @@ class SurfaceAdvectionOperator(AdvectionOperatorBase):
surf_v = sym.project(sym.DD_VOLUME, u.dd.with_qtag(None))(self.v)
return surface_advection_weak_flux(self.flux_type, u, surf_v)
- def penalty(self, u):
- surf_v = sym.project(sym.DD_VOLUME, u.dd.with_qtag(None))(self.v)
- return surface_penalty_flux(u, surf_v, tau=0.0)
-
def sym_operator(self):
u = sym.var("u")
def flux(pair):
return sym.project(pair.dd, face_dd)(self.flux(pair))
- def penalty(pair):
- return sym.project(pair.dd, face_dd)(self.penalty(pair))
-
face_dd = sym.DOFDesc(sym.FACE_RESTR_ALL, self.quad_tag)
quad_dd = sym.DOFDesc(sym.DTAG_VOLUME_ALL, self.quad_tag)
@@ -258,7 +243,6 @@ class SurfaceAdvectionOperator(AdvectionOperatorBase):
for n in range(self.ambient_dim))
- sym.FaceMassOperator(face_dd, sym.DD_VOLUME)(
flux(sym.int_tpair(u, self.quad_tag))
- + penalty(sym.int_tpair(u, self.quad_tag))
)
)
diff --git a/grudge/symbolic/primitives.py b/grudge/symbolic/primitives.py
index bc6c54d3..d06ae9f3 100644
--- a/grudge/symbolic/primitives.py
+++ b/grudge/symbolic/primitives.py
@@ -865,10 +865,6 @@ class TracePair:
def ext(self):
return self.exterior
- @property
- def jump(self):
- return self.int - self.ext
-
@property
def avg(self):
return 0.5*(self.int + self.ext)
--
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