docs: Example on pipe flow [skip tests]

.github/workflows/execute-examples-weekly.yml

@@ -173,7 +173,7 @@ jobs:
       - name: Execute Modeling_solidification_workflow.py
         run: |
           python examples/00-fluent/Modeling_solidification_workflow.py
-          
+
       - name: Execute catalytic_converter_workflow.py
         run: |
           python examples/00-fluent/catalytic_converter_workflow.py
@@ -194,6 +194,10 @@ jobs:
         run: |
           python examples/00-fluent/battery_pack.py
 
+      - name: Execute pipe_flow.py
+        run: |
+          python examples/00-fluent/pipe_flow.py
+
       # https://github.com/ansys/pyfluent/issues/4157
       # - name: Execute conjugate_heat_transfer.py
       #   run: |

doc/changelog.d/4883.documentation.md

@@ -0,0 +1 @@
+Example on pipe flow [skip tests]

doc/source/conf.py

@@ -152,7 +152,7 @@ def _stop_fluent_container(gallery_conf, fname):
     # path where to save gallery generated examples
     "gallery_dirs": ["examples"],
     # Pattern to search for example files
-    "filename_pattern": r"exhaust_system_settings_api\.py|external_compressible_flow\.py|mixing_elbow_settings_api\.py|modeling_cavitation\.py|species_transport\.py|ahmed_body_workflow\.py|brake\.py|DOE_ML\.py|radiation_headlamp\.py|parametric_static_mixer_1\.py|conjugate_heat_transfer\.py|tyler_sofrin_modes\.py|lunar_lander_thermal\.py|modeling_ablation\.py|frozen_rotor_workflow\.py|mixing_tank_workflow\.py|single_battery_cell_workflow\.py|steady_vortex\.py|fsi_1way_workflow\.py|transient_compressible_nozzle_workflow\.py|Electrolysis_Modeling_workflow\.py|catalytic_convertor_workflow\.py|battery_pack\.py",
+    "filename_pattern": r"exhaust_system_settings_api\.py|external_compressible_flow\.py|mixing_elbow_settings_api\.py|modeling_cavitation\.py|species_transport\.py|ahmed_body_workflow\.py|brake\.py|DOE_ML\.py|radiation_headlamp\.py|parametric_static_mixer_1\.py|conjugate_heat_transfer\.py|tyler_sofrin_modes\.py|lunar_lander_thermal\.py|modeling_ablation\.py|frozen_rotor_workflow\.py|mixing_tank_workflow\.py|single_battery_cell_workflow\.py|steady_vortex\.py|fsi_1way_workflow\.py|transient_compressible_nozzle_workflow\.py|Electrolysis_Modeling_workflow\.py|catalytic_convertor_workflow\.py|battery_pack\.py|pipe_flow\.py",
     # Do not execute examples
     "plot_gallery": False,
     # Remove the "Download all examples" button from the top level gallery

examples/00-fluent/pipe_flow.py

@@ -0,0 +1,318 @@
+# Copyright (C) 2021 - 2026 ANSYS, Inc. and/or its affiliates.
+# SPDX-License-Identifier: MIT
+#
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+""".. _flow_through_pipe:
+
+Flow of oil in a pipe through a lake
+=====================================
+"""
+
+# %%
+# Objective
+# ---------
+#
+# The primary objective of this study is to simulate **thermal energy transport**
+# in a circular pipe subjected to a constant wall temperature boundary condition.
+# The simulation represents oil flowing through a horizontal pipeline submerged in
+# icy lake water, where the surrounding cold environment maintains the pipe wall
+# at a uniform temperature. The analysis focuses on predicting the oil temperature
+# at the pipe exit after heat loss to the cold surroundings over the submerged
+# pipe length.
+#
+# The numerical results are validated against the analytical solution, demonstrating
+# the use of PyFluent as a verification and validation tool for classical
+# internal-flow heat-transfer problems.
+#
+# Problem Description
+# -------------------
+#
+# This simulation models the internal flow of oil through a horizontal circular
+# pipeline exposed to icy lake conditions. A 200-m-long section of the pipe passes
+# through lake water at 0°C. Due to the cold surroundings, measurements indicate
+# that the outer and inner pipe wall temperatures are very nearly uniform at 0°C.
+# The oil enters the lake section fully developed at a higher temperature and
+# undergoes convective cooling as it flows downstream.
+#
+# **Configuration:**
+#
+# - **Pipe diameter:** 0.3 m
+# - **Pipe length:** 200 m
+# - **Inlet velocity:** 2 m/s
+# - **Inlet temperature:** 20°C (293.15 K)
+# - **Wall temperature:** 0°C (273.15 K)
+#
+# **Assumptions:**
+#
+# - Steady operating conditions
+# - Thermal resistance of pipe material is negligible
+# - Inner surfaces of pipeline are smooth
+# - Flow is hydrodynamically developed when entering the lake section
+#
+# **Oil Properties at 20°C:**
+#
+# - Density (ρ): 888.1 kg/m³
+# - Kinematic viscosity (ν): 0.0009429 m²/s
+# - Specific heat (cp): 1880 J/kg·K
+# - Thermal conductivity (k): 0.145 W/m·K
+# - Prandtl number (Pr): 10863
+#
+# **Reynolds Number:**
+#
+# .. math::
+#
+#    Re = \frac{V D}{\nu} = \frac{(2 \text{ m/s})(0.3 \text{ m})}{9.429 \times 10^{-4} \text{ m}^2/\text{s}} = 636
+#
+# Since Re < 2300, the flow is laminar.
+#
+# .. image:: ../../_static/pipe_flow_1.png
+#    :align: center
+#    :alt: Schematic of pipe flow through lake
+
+# %%
+# Import modules
+# --------------
+
+import os
+
+import ansys.fluent.core as pyfluent
+from ansys.fluent.core import examples
+from ansys.fluent.core.solver import (
+    Energy,
+    FluidMaterials,
+    Initialization,
+    LineSurfaces,
+    RunCalculation,
+    VelocityInlets,
+    Viscous,
+    WallBoundaries,
+)
+from ansys.fluent.visualization import GraphicsWindow, Monitor, XYPlot
+
+# %%
+# Launch Fluent in solver mode
+# -----------------------------
+
+solver = pyfluent.launch_fluent(
+    precision=pyfluent.Precision.DOUBLE,
+    mode=pyfluent.FluentMode.SOLVER,
+    dimension=pyfluent.Dimension.TWO,
+)
+
+# %%
+# Read mesh
+# ---------
+
+mesh_file = examples.download_file(
+    "flow_through_pipe.msh",
+    "pyfluent/flow_through_pipe",
+    save_path=os.getcwd(),
+)
+
+solver.settings.file.read_mesh(file_name=mesh_file)
+
+# %%
+# Setup
+# -----
+#
+# Configure the simulation settings including turbulence model, boundary conditions,
+# and solution methods.
+#
+# Viscous Model
+# ^^^^^^^^^^^^^
+
+viscous = Viscous(solver)
+viscous.model = viscous.model.LAMINAR
+
+# %%
+# Energy model
+# ^^^^^^^^^^^^
+
+energy_model = Energy(solver)
+energy_model.enabled = True
+
+# %%
+# Materials
+# ^^^^^^^^^
+
+fluid_materials = FluidMaterials(solver)
+
+fluid_materials.rename(new="oil", old="air")
+fluid_materials["oil"] = {
+    "density": 888.1,
+    "viscosity": 0.0009429,
+    "specific_heat": 1880,
+    "thermal_conductivity": 0.145,
+}
+
+# %%
+# Boundary Conditions
+# ^^^^^^^^^^^^^^^^^^^
+#
+# Inlet velocity boundary
+# ^^^^^^^^^^^^^^^^^^^^^^^
+
+inlet_velocity_boundary = VelocityInlets(solver)
+
+inlet_velocity_boundary["inlet"] = {
+    "momentum": {"velocity_magnitude": 2},
+    "thermal": {"temperature": 293.15},
+}
+
+# %%
+# Wall boundary
+# ^^^^^^^^^^^^^
+
+wall_boundary = WallBoundaries(solver)
+
+wall_boundary["wall"] = {
+    "thermal": {"thermal_condition": "Temperature", "temperature": 273.15}
+}
+
+# %%
+# Initialize and run
+# ^^^^^^^^^^^^^^^^^^
+
+solution_initialization = Initialization(solver)
+solution_initialization.initialization_type = "hybrid"
+solution_initialization.initialize()
+
+calculation = RunCalculation(solver)
+calculation.iterate(iter_count=300)
+
+# %%
+# The solver was allowed to run for up to 300 iterations.
+# The solution converged after 146 iterations, as residuals
+# stabilized and key flow variables no longer changed so the solution terminated automatically.
+
+# %%
+# Results
+# -------
+#
+# Create line surface for temperature profile
+# ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+line_surface = LineSurfaces(solver)
+
+line_surface["line"] = {"p0": [0, 0.15, 0], "p1": [200, 0.15, 0]}
+
+# %%
+# Plot temperature distribution along the pipe
+# ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+plot_window = GraphicsWindow()
+
+xy_plot_object = XYPlot(
+    solver=solver,
+    surfaces=["line"],
+    y_axis_function="temperature",
+)
+plot_window.add_plot(
+    xy_plot_object, position=(0, 0), title="Temperature along the pipe"
+)
+
+residual = Monitor(solver=solver, monitor_set_name="residual")
+plot_window.add_plot(residual, position=(0, 1))
+
+plot_window.show()
+
+# %%
+# .. image:: ../../_static/pipe_flow_2.png
+#    :align: center
+#    :alt: temperature profile along center line
+
+# %%
+# Close session
+# -------------
+
+solver.exit()
+
+
+# %%
+# Numerical Validation
+# ====================
+#
+# Analytical Solution
+# -------------------
+#
+# The problem can be validated against analytical solutions for thermally developing
+# laminar flow in pipes with constant wall temperature.
+#
+#
+# **Thermal Entry Length:**
+#
+# For laminar flow with high Prandtl number:
+#
+# .. math::
+#
+#    L_t \approx 0.05 \, Re \, Pr \, D = 0.05 \times 636 \times 10863 \times 0.3 \approx 103{,}600 \text{ m}
+#
+# This is much greater than the pipe length (200 m), confirming thermally developing flow.
+#
+# **Nusselt Number:**
+#
+# For thermally developing laminar flow:
+#
+# .. math::
+#
+#    Nu = 3.66 + \frac{0.065 (D/L) Re \, Pr}{1 + 0.04 [(D/L) Re \, Pr]^{2/3}}
+#
+# .. math::
+#
+#    Nu = 3.66 + \frac{0.065(0.3/200) \times 636 \times 10{,}863}{1 + 0.04[(0.3/200) \times 636 \times 10{,}863]^{2/3}} = 33.7
+#
+# **Heat Transfer Coefficient:**
+#
+# .. math::
+#
+#    h = \frac{k \, Nu}{D} = \frac{0.145 \times 33.7}{0.3} = 16.3 \text{ W/m}^2\text{·K}
+#
+# **Exit Temperature:**
+#
+# Using energy balance for constant wall temperature:
+#
+# .. math::
+#
+#    T_e = T_s - (T_s - T_i) \exp\left(-\frac{h A_s}{\dot{m} c_p}\right)
+#
+# Where:
+#
+# - :math:`A_s = \pi D L = \pi (0.3)(200) = 188.5 \text{ m}^2`
+# - :math:`\dot{m} = \rho A_c V = 888 \times \frac{\pi}{4}(0.3)^2 \times 2 = 125.6 \text{ kg/s}`
+#
+# .. math::
+#
+#    T_e = 273.15 - (273.15 - 293.15) \exp\left(-\frac{16.3 \times 188.5}{125.6 \times 1880}\right) = 292.89 \text{ K} \, (19.74°\text{C})
+#
+# Discussion
+# ----------
+#
+# This example validates PyFluent's capability to accurately simulate convective heat transfer
+# in internal pipe flows involving high-Prandtl-number fluids in thermally developing flow regimes.
+# The PyFluent simulation was compared with the analytical solution for thermally developing laminar flow in a pipe with constant wall temperature.
+#
+# Analytical outlet temperature: :T_e = 292.74 K
+#
+# PyFluent outlet temperature: :T_e = 291.79 K
+#
+# Both approaches show only a small temperature drop over the 200-m pipe, consistent with the very long thermal entry length.
+
+# sphinx_gallery_thumbnail_path = '_static/pipe_flow_1.png'