OpenFOAM/C3/Simulating-Hagen-Poiseuille-flow/English

Tutorial: To simulate Hagen-Poiseuille flow in OpenFOAM.

Script and Narration : Saurabh S. Sawant

Keywords: Video tutorial,CFD.

Visual Cue	Narration
Slide 1:	Hello and welcome to the spoken tutorial on simulating Hagen-Poiseuille flow in OpenFOAM.
Slide 2 : Learning Objectives	In this tutorial we will see: To create and mesh 3D cylindrical pipe. To simulate the Hagen-Poiseuille flow having fixed pressure ratio across boundaries. To visualize the velocity contour in ParaView.
Slide 3: System Requirement	To record this tutorial I am using Linux Operating system Ubuntu 12.04 OpenFOAM version 2.1.1 ParaView version 3.12.0
Slide 4: Prerequisites	To practice this tutorial learner should have the knowledge of Basic Fluid Dynamics and Hagen-Poiseuille flow
Slide 5: Hagen-Poiseuille Flow Diagram Read aloud the given points and show the contents in the diagram with the mouse pointer.	Here is, Hagen-Poiseuille Flow Diagram. We can see the dimensions and boundaries of the pipe. Viscosity of fluid used, that is, water is given. Pressure at the inlet is 20 Pascals and outlet is 0 Pascals. As it is an incompressible flow, only the pressure difference is of importance.
Slide 6: Formulas and Analytical Solution Read aloud the given points	Formulas and Analytical Solution: For Hagen-Poiseuille flow, Pressure drop along the pipe is: (P1 minus P2) equals (32 mew Uaverage L) upon (D square) By substituting the values from the previous diagram, we get, Uaverage equals to 0.208 m/s Maximum Velocity is given as, Two times the average velocity, which would be, 0.416 m/s Reynolds Number for the flow is, Uaverage into D upon nu, that comes out to be, 2080 Hence, the flow is transient.
Slide 7: Transient Solver	Type of solver used here is, IcoFOAM It is a Transient Solver It is used for incompressible, laminar flow of Newtonian fluids.
Slide 8: Pressure Boundary Conditions	Pressure Boundary Conditions used, At Inlet: fixedPressure At Outlet: fixedPressure At Walls: ZeroGradient
Slide 9: Velocity Boundary Conditions	Velocity Boundary Conditions used, At Inlet: pressureInletVelocity At Outlet: zeroGradient At Walls: fixedValue
Show 3dpipe folder. Show the 3dpipe folder	For executing this case, First, Let's create the case directory in 'icoFoam' folder. Give it some name. I have named it as '3dpipe'.
Point the mouse pointer from lid driven folder to 3d pipe folder.	To know the location of this folder, go through the tutorial on lid driven cavity. Copy the '0' (zero), 'constant' and 'system' folders of lid driven cavity problem in the newly created folder.
Go inside the 3dpipe folder.	Let's go inside the '3dpipe' folder.
Hover the pointer over the folder inside the 3dpipe folder.	I have already copied the folders into my '3dpipe' folder and modified the files in it.
Go into the '0' folder and open P file and show it	Now, let's go into the '0' folder. And open the 'P' file. This is the pressure boundary condition file.
Show the pressure boundary condition file and show the dimensions inside it.	Note that the dimensions are in (meter square) per (second square) (m2/s2).
Show the pressure value written	Hence the pressure value in pascals is divided by density, that is, 1000 Kg/m3 (Kg per meter cube), and written here.
Close the file	Let's close the file.
Open U file in the same folder and show	File containing velocity boundary condition is as shown:
Close the file and come out of the '0' folder	Let's close the file and come out of the '0' folder.
Switch back to the slides	To see the blocking strategy, let me switch back to the slides.
Slide 10: Blocking Strategy Hover the pointer on the geometry and drag it towards the z direction.	To create a 3D geometry of a pipe I have made a 2D circular geometry and extruded the length in the z direction.
Point out the numbering pattern.	Numbering Pattern is as shown.
Minimize the slides	To see the blockMeshDict file, let's minimize the slides.
Go to folder 'constant' and then 'polyMesh' and open blockMeshDict file and show it.	Let's go into the folder 'constant', and then 'polyMesh'. Final blockMeshDict file is as shown:
Close the file and come out of the folder 'constant'	Let's close the file and come out of the 'constant' folder.
Open and show transportProperties file and point at the value viscosity value	We see the 'transportProperties' file. Note the dynamic viscosity value, here, is 1e-06.
Close the file and come out of the 'constant' folder.	Let's close the file and come out to the 'constant' folder.
Go into the system folder and open the controlDict file. Show it.	Let's go into the 'system' folder. Now, let's have a look at the 'controlDict' file.
Show time step value	The time step has been set to 1e-03. The solution converges after 18 seconds. The final time step is kept 19.
Close the file and the Home folder	Let's close the file. Let's close the 'Home' folder.
Press 'control', 'alt' and 't' keys altogether	Now to execute the case, we will, first, go inside the '3dpipe' folder through terminal.Let's open the terminal by pressing 'control', 'alt' and 't' keys, altogether.
Type run and press Enter in the terminal.	Type run and press Enter
Type cd (space) tutorials and press Enter	Type cd (space) tutorials and press Enter
Type cd (space) incompressible and press Enter	Type cd (space) incompressible and press Enter
Type cd (space) icoFoam and press Enter	Type cd (space) icoFoam and press Enter
Type cd (space) 3Dpipe and press Enter	Type cd (space) 3Dpipe and press Enter
Type blockMesh and press Enter	Now to create the mesh, type blockMesh and press Enter. Meshing has been done.
After the meshing is done, type icoFoam to start the iterations	To start the iterations type icoFoam and press Enter. We can see the iterations running.
After the iterations are done, type paraFoam for postprocessing the results and press Enter.	Iterations has been done. After the iterations end type paraFoam for postprocessing the results and press Enter.
Click on Apply.	Let's click on Apply on the left hand side of the Object inspector menu to see the geometry.
Rotate the geometry by pressing the button of the mouse and move it in the required direction.	Let's rotate the geometry for a better view.
Click on the active variable control menu and select U in the drop-down menu	Click on the active variable control menu and select U in the drop-down menu.
Click on play button	At the top, in VCR toolbar, click on Play button.
Go to Object Inspector menu, go to Display, click on Rescale data range	Go to Object Inspector menu, go to Display, click on Rescale data range.
go to the toolbar named common, click on Clips and press Apply	To view the half section, go to the toolbar named common, click on Clips and press Apply.
Open the color legent	Let's open the color legend.
	We can see the maximum velocity is near to the actual maximum velocity.
Go to Filters> Data Analysis> Plot Over Lines	To view the graph Go to Filters> Data Analysis> Plot Over Lines.
click on Y axis and press Apply	Let's click on Y axis and press Apply.
Point towards the parabolic profile	We see the parabolic profile for Hagen-Poiseuille flow.
Close the graph	Let's close the graph.
Close ParaView	Close ParaView.
Switch to the slides	Let's switch to the slides.
Slide 11: Summary	In this tutorial we have learned: To create 3D pipe geometry.To simulate Hagen-Poiseuille flow for a fixed pressure ratio. To visualize the velocity results in ParaView. This brings us to the end of the tutorial.
Slide 12 : Assignment	As an assignment, Change the geometry parameters such as length and diameter. Change the corresponding pressure ratio. Use the fluid of different viscosity.
Slide 13: About Spoken tutorials	* Watch the video available at the following link It summarises the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it
Slide 14: About Spoken tutorials	The Spoken Tutorial Project Team Conducts workshops using spoken tutorials Gives certificates for those who pass an online test For more details, please write to contact at spoken hyphen tutorial dot org
Slide 15: Acknowledgement	Spoken Tutorial Project is a part of the Talk to a Teacher project It is supported by the National Mission on Education through ICT, MHRD, Government of India More information on this Mission is available at spoken hyphen tutorial dot org slash NMEICT hyphen Intro

Contributors and Content Editors

DeepaVedartham, Nancyvarkey, P12575, Sneha