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"source": [
"# Unsteady 2D Cylinder\n",
"\n",
"This tutorial shows how to run a 2D unsteady simulation of a cylinder.\n",
"\n",
"**Note:** The settings in this example are by no means a validation setup; they are crafted to showcase the capabilities of Flow360 and we have intentionally reduced node count and example FC cost. For rigorous validation, modify the settings as needed."
],
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"metadata": {},
"source": [
"## 1. Create Project from volume mesh\n",
"- Load Python libraries and Flow360 client. If you use environment variables or tokens, initialize them here so later API calls can authenticate.\n",
"- Project is created from a volume mesh"
],
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{
"cell_type": "code",
"metadata": {},
"source": [
"import flow360 as fl\n",
"from flow360.examples import Cylinder2D\n",
"\n",
"Cylinder2D.get_files()\n",
"\n",
"\n",
"project = fl.Project.from_volume_mesh(Cylinder2D.mesh_filename, name=\"Unsteady 2D Cylinder\")\n",
"\n",
"vm = project.volume_mesh"
],
"execution_count": 1,
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"[17:47:54] INFO: VolumeMesh successfully submitted: \n",
" type = Volume Mesh \n",
" name = Unsteady 2D Cylinder from Python \n",
" id = vm-cf43d640-0fb0-44b8-8c39-3d026f7529ed \n",
" status = uploaded \n",
" \n",
"\n"
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"\u001b[2;36m[17:47:54]\u001b[0m\u001b[2;36m \u001b[0m\u001b[36mINFO\u001b[0m: VolumeMesh successfully submitted: \n",
"\u001b[2;36m \u001b[0m type = Volume Mesh \n",
"\u001b[2;36m \u001b[0m name = Unsteady 2D Cylinder from Python \n",
"\u001b[2;36m \u001b[0m id = vm-\u001b[93mcf43d640-0fb0-44b8-8c39-3d026f7529ed\u001b[0m \n",
"\u001b[2;36m \u001b[0m status = uploaded \n",
"\u001b[2;36m \u001b[0m \n"
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{
"cell_type": "markdown",
"metadata": {},
"source": [
"## 2. Define time settings\n",
"To run an unsteady simulation, we need to define a step size and the total number of steps. Additionally, it is also possible to define the maximum number of pseudo steps done between two physical steps."
],
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{
"cell_type": "code",
"metadata": {},
"source": [
"with fl.SI_unit_system:\n",
" time_settings = fl.Unsteady(\n",
" step_size=2,\n",
" steps=20,\n",
" max_pseudo_steps=40,\n",
" )"
],
"execution_count": 2,
"outputs": [
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"output_type": "display_data",
"data": {
"text/html": [
"[17:48:13] INFO: using: SI unit system for unit inference. \n",
"\n"
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"text/plain": [
"\u001b[2;36m[17:48:13]\u001b[0m\u001b[2;36m \u001b[0m\u001b[36mINFO\u001b[0m: using: SI unit system for unit inference. \n"
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{
"cell_type": "markdown",
"metadata": {},
"source": [
"## 3. Define boundary conditions and solver settings\n",
"The models section includes the boundary conditions definition and the solver settings."
],
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{
"cell_type": "code",
"metadata": {},
"source": [
"with fl.SI_unit_system:\n",
" models = [\n",
" fl.Fluid(\n",
" navier_stokes_solver=fl.NavierStokesSolver(\n",
" absolute_tolerance=1e-9,\n",
" linear_solver=fl.LinearSolver(max_iterations=25),\n",
" ),\n",
" turbulence_model_solver=fl.NoneSolver(),\n",
" ),\n",
" fl.Wall(surfaces=[vm[\"fluid/wall\"]]),\n",
" fl.Freestream(surfaces=[vm[\"fluid/farfield\"]]),\n",
" fl.SlipWall(surfaces=[vm[\"fluid/periodic_0_l\"], vm[\"fluid/periodic_0_r\"]]),\n",
" ]"
],
"execution_count": 3,
"outputs": [
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"output_type": "display_data",
"data": {
"text/html": [
" INFO: using: SI unit system for unit inference. \n",
"\n"
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"\u001b[2;36m \u001b[0m\u001b[2;36m \u001b[0m\u001b[36mINFO\u001b[0m: using: SI unit system for unit inference. \n"
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{
"cell_type": "markdown",
"metadata": {},
"source": [
"## 4. Define SimulationParams\n",
"- The simulation parameters are defined in the python class fl.SimulationParams()\n",
"- THe previous settings are included as well as the operating conditions, outputs and reference geometries."
],
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{
"cell_type": "code",
"metadata": {},
"source": [
"with fl.SI_unit_system:\n",
" params = fl.SimulationParams(\n",
" operating_condition=fl.AerospaceCondition.from_mach_reynolds(\n",
" reynolds_mesh_unit=50, mach=0.1, project_length_unit=fl.u.m\n",
" ),\n",
" models=models,\n",
" time_stepping=time_settings,\n",
" outputs=[\n",
" fl.SurfaceOutput(output_fields=[\"Cp\"], surfaces=[vm[\"*\"]]),\n",
" fl.VolumeOutput(\n",
" output_fields=[\n",
" \"primitiveVars\",\n",
" \"vorticity\",\n",
" \"residualNavierStokes\",\n",
" \"T\",\n",
" \"Cp\",\n",
" \"mut\",\n",
" ],\n",
" ),\n",
" ],\n",
" reference_geometry=fl.ReferenceGeometry(\n",
" area=20, moment_center=[0, 0, 0], moment_length=[1, 1, 1]\n",
" ),\n",
" )"
],
"execution_count": 4,
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" INFO: using: SI unit system for unit inference. \n",
"\n"
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" INFO: Density and viscosity were calculated based on input data, ThermalState will be automatically \n",
" created. \n",
"\n"
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"\u001b[2;36m \u001b[0m\u001b[2;36m \u001b[0m\u001b[36mINFO\u001b[0m: Density and viscosity were calculated based on input data, ThermalState will be automatically \n",
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"cell_type": "markdown",
"metadata": {},
"source": [
"## 5. Run Case"
],
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"cell_type": "code",
"metadata": {},
"source": [
"case = project.run_case(params, \"Unsteady 2D Cylinder case from Python\")"
],
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"[17:48:15] INFO: Successfully submitted: \n",
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