perf: retain exact flow caches and compiled targets

tests/test_amesim_pnl0002_pnl0003_component.py

@@ -320,6 +320,38 @@ class AmesimPnl0003ComponentTests(unittest.TestCase):
         self.assertLess(abs(above - below), abs(above) * 0.05)
         self.assertEqual(equal, 0.0)
 
+    def test_exact_repeated_center_flow_inversion_is_cached(self) -> None:
+        pipe = AmesimPnl0003("pnl_3", self.medium)
+        pipe._mass_flow_for_pressure_drop.cache_clear()
+
+        first = pipe._mass_flow_for_pressure_drop(
+            1000.0,
+            density=1.2,
+            temperature=300.0,
+        )
+        after_first = pipe._mass_flow_for_pressure_drop.cache_info()
+        second = pipe._mass_flow_for_pressure_drop(
+            1000.0,
+            density=1.2,
+            temperature=300.0,
+        )
+        after_second = pipe._mass_flow_for_pressure_drop.cache_info()
+        changed_temperature = pipe._mass_flow_for_pressure_drop(
+            1000.0,
+            density=1.2,
+            temperature=400.0,
+        )
+        after_temperature_change = pipe._mass_flow_for_pressure_drop.cache_info()
+
+        self.assertEqual(first, second)
+        self.assertEqual(after_first.misses, 1)
+        self.assertEqual(after_second.hits, after_first.hits + 1)
+        self.assertNotEqual(changed_temperature, second)
+        self.assertEqual(
+            after_temperature_change.misses,
+            after_second.misses + 1,
+        )
+
     def test_pressure_flow_residuals_bind_both_port_pressures_to_states(self) -> None:
         pipe = AmesimPnl0003("pnl_3", self.medium)
         pipe.properties_1()