Corrected gallilean correction

lbmpy/turbulence_models.py

@@ -25,6 +25,14 @@ def add_smagorinsky_model(collision_rule, smagorinsky_constant, omega_output_fie
     tau_0 = sp.Symbol("tau_0_")
     second_order_neq_moments = sp.Symbol("Pi")
     rho = method.zeroth_order_equilibrium_moment_symbol if method.conserved_quantity_computation.compressible else 1
+
+    symbols = set()
+    for eq in collision_rule:
+        symbols.add(eq.lhs)
+
+    if sp.Symbol('rho') not in symbols and sp.Symbol('m_00') in symbols:
+        collision_rule.subexpressions += [Assignment(sp.Symbol('rho'), sp.Symbol('m_00'))]
+
     adapted_omega = sp.Symbol("smagorinsky_omega")
 
     collision_rule = collision_rule.new_with_substitutions({omega_s: adapted_omega})