No need to pass velocity to momentum balance

Author: danshapero

src/icepack2/model/variational.py

@@ -59,19 +59,18 @@ def calving_terminus(**kwargs):
 
 def momentum_balance(**kwargs):
     field_names = (
-        "velocity",
         "membrane_stress",
         "basal_stress",
         "thickness",
         "surface",
         "test_function",
     )
-    u, M, τ, h, s, v = map(kwargs.get, field_names)
+    M, τ, h, s, v = map(kwargs.get, field_names)
 
     ε = sym(grad(v))
     cell_balance = (-h * inner(M, ε) + inner(τ - ρ_I * g * h * grad(s), v)) * dx
 
-    mesh = ufl.domain.extract_unique_domain(u)
+    mesh = ufl.domain.extract_unique_domain(v)
     ν = FacetNormal(mesh)
     facet_balance = ρ_I * g * avg(h) * inner(jump(s, ν), avg(v)) * dS