add interpolation of HTC and T bulk

README.md

@@ -9,6 +9,8 @@ A Python library for interpolating physical field data (electromagnetic forces,
 - **Support for multiple load types**: 
   - EM forces (3-component vector fields)
   - Heat flux (scalar fields)
+  - Heat generation (volumetric)
+  - Heat Transfer Coefficient + bulk fluid temperature (convection BCs)
 - **Export to ANSYS APDL**: Direct export of interpolated results in APDL format
 - **Visualization**: Built-in VTK export for ParaView or PyVista visualization
 - **Efficient**: KDTree-based spatial queries for fast neighbor searches
@@ -62,9 +64,10 @@ interpolator.build_vtk_output(outdir="vtk_output")
 
 Complete working examples with sample data are available in the [`doc/`](doc/) folder:
 
-- **[Heat Flux Example](doc/heat_flux/)**: Scalar field interpolation using the AVERAGE kernel
-- **[Heat Generation Example](doc/heat_gen/)**: Volumetric heat generation using the CLOSEST kernel
-- **[EM Force Example](doc/em_force/)**: Vector field interpolation with glyph visualization
+- **[Heat Flux Example](doc/heat_flux/heat_flux.ipynb)**: Scalar field interpolation using the AVERAGE kernel
+- **[Heat Generation Example](doc/heat_gen/heat_gen.ipynb)**: Volumetric heat generation using the CLOSEST kernel
+- **[EM Force Example](doc/em_force/em_force.ipynb)**: Vector field interpolation with glyph visualization
+- **[HTC Example](doc/htc/htc.ipynb)**: Convection boundary condition interpolation (HTC + bulk fluid temperature) 
 
 Each example includes:
 - Sample mesh files
@@ -99,6 +102,7 @@ A value is assigned to each destination point based on source neighbours
     interpreted as force densities and will be multiplied by the volume.
 - `HEAT_FLUX`: Scalar fields for surface heat flux
 - `HEAT_GEN`: Scalar fields for volumetric heat generation
+- `HTC`: 2-component convection boundary condition — Heat Transfer Coefficient and bulk fluid (reference) temperature. Exported as `SFE,,CONV,1` and `SFE,,CONV,2` in APDL.
 
 ## File Format
 

doc/htc/destination_mesh.txt

@@ -0,0 +1,76 @@
+Node_ID X Y Z
+101 0.25 0.33 0.00
+102 0.25 1.00 0.00
+103 0.25 1.67 0.00
+104 0.25 2.33 0.00
+105 0.25 3.00 0.00
+106 0.25 3.67 0.00
+107 0.25 4.34 0.00
+108 0.25 5.00 0.00
+109 0.25 5.67 0.00
+110 0.25 6.34 0.00
+111 0.25 7.00 0.00
+112 0.25 7.67 0.00
+113 0.25 8.34 0.00
+114 0.25 9.00 0.00
+115 0.25 9.67 0.00
+116 0.75 0.33 0.00
+117 0.75 1.00 0.00
+118 0.75 1.67 0.00
+119 0.75 2.33 0.00
+120 0.75 3.00 0.00
+121 0.75 3.67 0.00
+122 0.75 4.34 0.00
+123 0.75 5.00 0.00
+124 0.75 5.67 0.00
+125 0.75 6.34 0.00
+126 0.75 7.00 0.00
+127 0.75 7.67 0.00
+128 0.75 8.34 0.00
+129 0.75 9.00 0.00
+130 0.75 9.67 0.00
+131 1.25 0.33 0.00
+132 1.25 1.00 0.00
+133 1.25 1.67 0.00
+134 1.25 2.33 0.00
+135 1.25 3.00 0.00
+136 1.25 3.67 0.00
+137 1.25 4.34 0.00
+138 1.25 5.00 0.00
+139 1.25 5.67 0.00
+140 1.25 6.34 0.00
+141 1.25 7.00 0.00
+142 1.25 7.67 0.00
+143 1.25 8.34 0.00
+144 1.25 9.00 0.00
+145 1.25 9.67 0.00
+146 1.75 0.33 0.00
+147 1.75 1.00 0.00
+148 1.75 1.67 0.00
+149 1.75 2.33 0.00
+150 1.75 3.00 0.00
+151 1.75 3.67 0.00
+152 1.75 4.34 0.00
+153 1.75 5.00 0.00
+154 1.75 5.67 0.00
+155 1.75 6.34 0.00
+156 1.75 7.00 0.00
+157 1.75 7.67 0.00
+158 1.75 8.34 0.00
+159 1.75 9.00 0.00
+160 1.75 9.67 0.00
+161 2.25 0.33 0.00
+162 2.25 1.00 0.00
+163 2.25 1.67 0.00
+164 2.25 2.33 0.00
+165 2.25 3.00 0.00
+166 2.25 3.67 0.00
+167 2.25 4.34 0.00
+168 2.25 5.00 0.00
+169 2.25 5.67 0.00
+170 2.25 6.34 0.00
+171 2.25 7.00 0.00
+172 2.25 7.67 0.00
+173 2.25 8.34 0.00
+174 2.25 9.00 0.00
+175 2.25 9.67 0.00

doc/htc/source_data/htc_data.txt

@@ -0,0 +1,31 @@
+Node_ID X Y Z HTC Tref
+1 0.50 0.50 0.00 150.00 310.00
+2 0.50 1.50 0.00 155.00 312.00
+3 0.50 2.50 0.00 162.00 315.00
+4 0.50 3.50 0.00 170.00 318.00
+5 0.50 4.50 0.00 178.00 320.00
+6 0.50 5.50 0.00 185.00 322.00
+7 0.50 6.50 0.00 190.00 325.00
+8 0.50 7.50 0.00 196.00 328.00
+9 0.50 8.50 0.00 200.00 330.00
+10 0.50 9.50 0.00 205.00 332.00
+11 1.50 0.50 0.00 158.00 311.00
+12 1.50 1.50 0.00 163.00 313.00
+13 1.50 2.50 0.00 169.00 316.00
+14 1.50 3.50 0.00 177.00 319.00
+15 1.50 4.50 0.00 184.00 321.00
+16 1.50 5.50 0.00 191.00 323.00
+17 1.50 6.50 0.00 198.00 326.00
+18 1.50 7.50 0.00 204.00 329.00
+19 1.50 8.50 0.00 209.00 331.00
+20 1.50 9.50 0.00 214.00 333.00
+21 2.50 0.50 0.00 165.00 312.00
+22 2.50 1.50 0.00 170.00 314.00
+23 2.50 2.50 0.00 176.00 317.00
+24 2.50 3.50 0.00 183.00 320.00
+25 2.50 4.50 0.00 190.00 322.00
+26 2.50 5.50 0.00 197.00 324.00
+27 2.50 6.50 0.00 204.00 327.00
+28 2.50 7.50 0.00 210.00 330.00
+29 2.50 8.50 0.00 215.00 332.00
+30 2.50 9.50 0.00 220.00 334.00

src/interpcore/config.py

@@ -19,6 +19,7 @@ class INTERPOLATED_LOAD_TYPE(Enum):
     EM_FORCE = "EM-Force"
     HEAT_FLUX = "Heat Flux"
     HEAT_GEN = "Heat Generation"
+    HTC = "Heat Transfer Coefficient"
 
 
 class INTERPOLATION_KERNEL(Enum):
@@ -85,5 +86,7 @@ def __post_init__(self):
             self.num_components = 1
         elif self.interpolated_load == INTERPOLATED_LOAD_TYPE.HEAT_GEN:
             self.num_components = 1
+        elif self.interpolated_load == INTERPOLATED_LOAD_TYPE.HTC:
+            self.num_components = 2
         else:
             raise ValueError(f"Unsupported load type: {self.interpolated_load}")

src/interpcore/interpolator.py

@@ -243,5 +243,10 @@ def _select_template(interpolated_load: INTERPOLATED_LOAD_TYPE) -> list[str]:
         return [
             "BFE, {}, HGEN,, {}\n",
         ]
+    elif interpolated_load == INTERPOLATED_LOAD_TYPE.HTC:
+        return [
+            "SFE, {},, CONV, 1, {}\n",  # HTC
+            "SFE, {},, CONV, 2, {}\n",  # TEMP
+        ]
     else:
         raise NotImplementedError(f"Unsupported load type: {interpolated_load}")

tests/test_interpolator.py

@@ -61,6 +61,20 @@ def sample_config_heat_gen():
     )
 
 
+@pytest.fixture
+def sample_config_htc():
+    """Create a sample configuration for HTC interpolation"""
+    return InterpolationConfig(
+        method=QUERY_TYPE.K,
+        param=3,
+        max_distance=2.0,
+        coincidence_tolerance=1e-6,
+        kernel=INTERPOLATION_KERNEL.DISTANCE_WEIGHTED,
+        multithread=False,
+        interpolated_load=INTERPOLATED_LOAD_TYPE.HTC,
+    )
+
+
 @pytest.fixture
 def create_sample_mesh_files(temp_dir):
     """Create sample mesh and data files for testing"""
@@ -156,6 +170,38 @@ def create_sample_heat_gen_files(temp_dir):
     }
 
 
+@pytest.fixture
+def create_sample_htc_files(temp_dir):
+    """Create sample mesh and HTC data files for testing"""
+    # Create destination mesh file
+    dest_mesh = temp_dir / "destination_mesh.txt"
+    dest_content = """Node_ID X Y Z
+501 0.0 0.0 0.0
+502 1.0 0.0 0.0
+503 2.0 0.0 0.0
+504 0.0 1.0 0.0
+"""
+    dest_mesh.write_text(dest_content)
+
+    # Create source data folder
+    src_folder = temp_dir / "htc_data"
+    src_folder.mkdir()
+
+    # Create source data file with HTC and reference temperature (2 components)
+    src_file = src_folder / "htc_001.txt"
+    src_content = """Node_ID X Y Z HTC Tref
+1 0.5 0.5 0.0 250.0 300.0
+2 1.5 0.5 0.0 300.0 310.0
+3 0.5 1.5 0.0 275.0 305.0
+"""
+    src_file.write_text(src_content)
+
+    return {
+        "dest_mesh": str(dest_mesh),
+        "src_folder": str(src_folder),
+    }
+
+
 class TestInterpolator:
     """Tests for Interpolator class"""
 
@@ -267,6 +313,25 @@ def test_interpolate_all_with_em_force(
         result = interpolator.interpolated_results["force_001"]
         assert result["interpolated"].shape[1] == 3  # EM force has 3 components
 
+    def test_interpolate_all_with_htc(self, create_sample_htc_files, sample_config_htc):
+        """Test interpolation with HTC data (2 components: HTC and Tref)"""
+        file_idx = {"ids": 0, "dest_x": 1, "src_x": 1, "val": 4}
+        interpolator = Interpolator(
+            path_to_src_folder=create_sample_htc_files["src_folder"],
+            path_to_dest_mesh=create_sample_htc_files["dest_mesh"],
+            config=sample_config_htc,
+            file_idx=file_idx,
+        )
+
+        interpolator.interpolate_all()
+
+        assert interpolator.interpolated_results is not None
+        result = interpolator.interpolated_results["htc_001"]
+        assert "interpolated" in result
+        assert "unmapped" in result
+        assert result["interpolated"].shape[0] > 0
+        assert result["interpolated"].shape[1] == 2  # HTC has 2 components
+
     def test_export_to_ansys_without_interpolation(
         self, create_sample_mesh_files, sample_config_heat_flux, temp_dir
     ):
@@ -371,6 +436,34 @@ def test_export_to_ansys_heat_gen(
         assert "HGEN" in content
         assert "BF" in content
 
+    def test_export_to_ansys_htc(
+        self, create_sample_htc_files, sample_config_htc, temp_dir
+    ):
+        """Test exporting HTC results to ANSYS format"""
+        file_idx = {"ids": 0, "dest_x": 1, "src_x": 1, "val": 4}
+        interpolator = Interpolator(
+            path_to_src_folder=create_sample_htc_files["src_folder"],
+            path_to_dest_mesh=create_sample_htc_files["dest_mesh"],
+            config=sample_config_htc,
+            file_idx=file_idx,
+        )
+
+        interpolator.interpolate_all()
+
+        output_dir = temp_dir / "output"
+        output_dir.mkdir()
+        interpolator.export_to_ansys(output_dir)
+
+        # Check that output file was created
+        output_files = list(output_dir.glob("interpolated_*.txt"))
+        assert len(output_files) == 1
+        assert output_files[0].name == "interpolated_htc_001.txt"
+
+        # Check file content format (should have CONV)
+        content = output_files[0].read_text()
+        assert "CONV" in content
+        assert "SFE" in content
+
     def test_build_vtk_output_without_interpolation(
         self, create_sample_mesh_files, sample_config_heat_flux
     ):
@@ -500,6 +593,16 @@ def test_select_template_heat_gen(self):
         assert "HGEN" in templates[0]
         assert "BFE" in templates[0]
 
+    def test_select_template_htc(self):
+        """Test template selection for HTC"""
+        templates = _select_template(INTERPOLATED_LOAD_TYPE.HTC)
+
+        assert len(templates) == 2
+        assert "CONV" in templates[0]
+        assert "SFE" in templates[0]
+        assert "CONV" in templates[1]
+        assert "SFE" in templates[1]
+
     def test_select_template_unsupported_type(self):
         """Test that unsupported load types raise NotImplementedError"""