Restrict sim_data to 3D two-fluid 5/6-equation cases

toolchain/mfc/case_validator.py

@@ -2669,6 +2669,16 @@ def check_surface_tension_post(self):
 
         self.prohibit(cf_wrt and not surface_tension, "cf_wrt can only be enabled if surface_tension is enabled")
 
+    def check_sim_data(self):
+        """Checks interface/energy data output constraints (post-process)"""
+        if self.get("sim_data", "F") != "T":
+            return
+
+        # s_write_energy_data_file uses dz and s_write_intf_data_file reads alpha_2 at eqn_idx%E + 2
+        self.prohibit(self.get("p", 0) == 0, "sim_data requires p > 0 (3D)")
+        self.prohibit(self.get("num_fluids") != 2, "sim_data requires num_fluids = 2")
+        self.prohibit(self.get("model_eqns") not in [2, 3], "sim_data requires model_eqns = 2 or 3")
+
     def check_no_flow_variables(self):
         """Checks that at least one flow variable is selected (post-process)"""
         rho_wrt = self.get("rho_wrt", "F") == "T"
@@ -3106,6 +3116,7 @@ def validate_post_process(self):
         self.check_liutex_post()
         self.check_schlieren()
         self.check_surface_tension_post()
+        self.check_sim_data()
         self.check_no_flow_variables()
 
     def validate(self, stage: str = "simulation"):

toolchain/mfc/lint_docs.py

@@ -446,6 +446,7 @@ def check_physics_docs_coverage(repo_root: Path) -> list[str]:
         "check_partial_domain",  # output format settings
         "check_perturb_density",  # parameter pairing validation
         "check_qm",  # output dimension requirements
+        "check_sim_data",  # output dimension requirements
         "check_chemistry",  # runtime Cantera validation only
         # Awaiting proper physics documentation (math, references, explanation)
         "check_adaptive_time_stepping",

toolchain/mfc/test_case_validator.py

@@ -704,3 +704,50 @@ def test_rejects_isothermal_wall_without_any_heat_path(self):
             {**BASE, "bc_x%beg": -16, "bc_x%end": -16, "bc_x%isothermal_in": "T", "bc_x%Twall_in": 300.0},
             "requires a heat-conduction path",
         )
+
+
+class TestSimData(ConstraintTestCase):
+    """sim_data's interface and energy writers assume a 3D two-fluid 5- or 6-equation case."""
+
+    GOOD = {
+        **BASE_2D,
+        **{k: v for k, v in TWO_FLUID.items() if k not in BASE},
+        "num_fluids": 2,
+        "p": 50,
+        "bc_z%beg": -1,
+        "bc_z%end": -1,
+        "z_domain%beg": 0.0,
+        "z_domain%end": 1.0,
+        "patch_icpp(1)%z_centroid": 0.5,
+        "patch_icpp(1)%length_z": 1.0,
+        "patch_icpp(1)%vel(3)": 0.0,
+        "rho_wrt": "T",
+        "sim_data": "T",
+    }
+
+    def errors_for(self, params) -> str:
+        """Validate at the post_process stage, where sim_data is read."""
+        validator = CaseValidator(dict(params))
+        try:
+            validator.validate("post_process")
+        except CaseConstraintError as exc:
+            return str(exc)
+        return ""
+
+    def test_accepts_3d_two_fluid(self):
+        self.assertAccepts(self.GOOD)
+
+    def test_accepts_six_equation(self):
+        self.assertAccepts({**self.GOOD, "model_eqns": 3})
+
+    def test_rejects_2d(self):
+        self.assertRejects({**self.GOOD, "p": 0}, "sim_data requires p > 0 (3D)")
+
+    def test_rejects_one_fluid(self):
+        self.assertRejects({**self.GOOD, "num_fluids": 1}, "sim_data requires num_fluids = 2")
+
+    def test_rejects_gamma_law(self):
+        self.assertRejects({**self.GOOD, "model_eqns": 1}, "sim_data requires model_eqns = 2 or 3")
+
+    def test_not_tripped_when_disabled(self):
+        self.assertAccepts({**BASE_2D, "rho_wrt": "T", "sim_data": "F"})