diff options
Diffstat (limited to 'boltzgen/lbm/__init__.py')
| -rw-r--r-- | boltzgen/lbm/__init__.py | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/boltzgen/lbm/__init__.py b/boltzgen/lbm/__init__.py index 8206baa..3f608cb 100644 --- a/boltzgen/lbm/__init__.py +++ b/boltzgen/lbm/__init__.py @@ -9,8 +9,14 @@ def assign(names, definitions): return list(map(lambda x: Assignment(*x), zip(names, definitions))) class LBM: - def __init__(self, descriptor): + def __init__(self, descriptor, tau, optimize = True): self.descriptor = descriptor + self.tau = tau + self.optimize = optimize + + if self.tau <= 0.5: + raise Exception('Relaxation time must be larger than 0.5') + self.f_next = symarray('f_next', descriptor.q) self.f_curr = symarray('f_curr', descriptor.q) @@ -20,7 +26,10 @@ class LBM: if not hasattr(descriptor, 'c_s'): self.descriptor.c_s = c_s(descriptor.d, descriptor.c, self.descriptor.w) - def moments(self, optimize = True): + def moments(self, optimize = None): + if optimize is None: + optimize = self.optimize + rho = symbols('rho') u = Matrix(symarray('u', self.descriptor.d)) @@ -35,10 +44,16 @@ class LBM: else: return ([], exprs) - def equilibrium(self): + def equilibrium(self, resolve_moments = False): rho = symbols('rho') u = Matrix(symarray('u', self.descriptor.d)) + if resolve_moments: + moments = self.moments(optimize = False)[1] + rho = moments[0].rhs + for i, m in enumerate(moments[1:]): + u[i] = m.rhs + f_eq = [] for i, c_i in enumerate(self.descriptor.c): @@ -50,11 +65,11 @@ class LBM: return f_eq - def bgk(self, tau, f_eq, optimize = True): - if tau <= 0.5: - raise Exception('Relaxation time must be larger than 0.5') + def bgk(self, f_eq, optimize = None): + if optimize is None: + optimize = self.optimize - exprs = [ self.f_curr[i] + 1/tau * (f_eq_i - self.f_curr[i]) for i, f_eq_i in enumerate(f_eq) ] + exprs = [ self.f_curr[i] + 1/self.tau * (f_eq_i - self.f_curr[i]) for i, f_eq_i in enumerate(f_eq) ] if optimize: subexprs, f = cse(exprs, optimizations=optimizations.custom) |