def test_d3q19_2nd_order_bgk(self):
"""Verifies that the entropic equilibrium for D3Q19 is the same
as the LBGK equilibrium up to 2nd order in velocity."""
grid = sym.D3Q19
bgk = sym_equilibrium.bgk_equilibrium(grid, cfg)
elbm = sym_equilibrium.elbm_d3q19_equilibrium(grid, order=2)
for i, (elbm_ex, bgk_ex) in enumerate(zip(elbm.expression, bgk.expression)):
for x in elbm.local_vars:
elbm_ex = elbm_ex.subs({x.lhs: x.rhs})
elbm_trunc = sym_codegen.truncate_velocity(Poly(elbm_ex), order=2).subs({
'vsq': sym.S.vx**2 + sym.S.vy**2 + sym.S.vz**2})
self.assertEqual(elbm_trunc.expand(), bgk_ex.expand(),
'%d component' % i)
def test_d3q19_2nd_order_bgk(self):
"""Verifies that the entropic equilibrium for D3Q19 is the same
as the LBGK equilibrium up to 2nd order in velocity."""
grid = sym.D3Q19
bgk = sym_equilibrium.bgk_equilibrium(grid, cfg)
elbm = sym_equilibrium.elbm_d3q19_equilibrium(grid, order=2)
for i, (elbm_ex,
bgk_ex) in enumerate(zip(elbm.expression, bgk.expression)):
for x in elbm.local_vars:
elbm_ex = elbm_ex.subs({x.lhs: x.rhs})
elbm_trunc = sym_codegen.truncate_velocity(
Poly(elbm_ex),
order=2).subs({'vsq': sym.S.vx**2 + sym.S.vy**2 + sym.S.vz**2})
self.assertEqual(elbm_trunc.expand(), bgk_ex.expand(),
'%d component' % i)
def test_d3q19_moments(self):
grid = sym.D3Q19
elbm = sym_equilibrium.elbm_d3q19_equilibrium(grid, order=8)
self._verify_moments(grid, elbm)
def test_d3q19_moments(self):
grid = sym.D3Q19
elbm = sym_equilibrium.elbm_d3q19_equilibrium(grid, order=8)
self._verify_moments(grid, elbm)
