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OpenFOAM Baby Steps - 3D Flow Over a Wing (Episode 2)

3D Airflow Over a Wing 3D Airflow Over a Wing

This is the second in a series.  You can start the series here.   The series follows my journey figuring out how to use OpenFOAM for something more than repeating tutorials that already exist!    Sometimes that journey gets a little rocky!   :)

The Final Wing Design

The setup is similar to the 2D cylinder in last episode.  This time, I used the Airplane Design Workbench in FreeCAD (if you don't see it listed, check your Tools -> Addon Manager).  I created a wing with two segments, using the provided NACA 2412 airfoil.  The specifics are not terribly important; my goal was to get a mesh to compute and get the OpenFOAM solution to converge.

The CFD setup was straightforward:  steady-state, incompressible flow.  I created a 'Symmetry' constraint on the near wall.  The far, top and bottom walls had an inviscid constraint.  The flow went in the +X direction, and the appropriate faces constrained as Inlet and Outlet.  The wing surfaces all had a viscoud (no-slip) constraint.

Closeup of Mesh Refinement Around Wing
Mesh of the Domain and Wing Section
After wrapping the wing inside a calculation domain, and adding some mesh refinements near the wing surface, the grid appeared as shown.  Since my goal was only to get a valid solution, rather than the 'right' solution, I kept the mesh relatively course.​ The refinement around the wing was a bit excessive.  Also, in retrospect, the domain could have been reduced by about 50% vertically and along the wingspan.  But both the mesh and CFD calculations were fairly rapid.

​Taking the results into ParaView, I learned what the Clip filter does!  Then I added arrow glyphs to represent velocity.  I did not figure out how to avoid the short, stubby arrows, but that is a problem for future me. 

OpenFOAM Results In ParaView - Velocity Field
OpenFOAM Baby Steps - Calculating Lift and Drag (E...
OpenFOAM Baby Steps - 2D Flow Over a Cylinder

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Sunday, 27 September 2020

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Rick's Blog

Featured 

OpenFOAM Baby Steps - 3D Flow Over a Wing (Episode 2)

3D Airflow Over a Wing 3D Airflow Over a Wing

This is the second in a series.  You can start the series here.   The series follows my journey figuring out how to use OpenFOAM for something more than repeating tutorials that already exist!    Sometimes that journey gets a little rocky!   :)

The Final Wing Design

The setup is similar to the 2D cylinder in last episode.  This time, I used the Airplane Design Workbench in FreeCAD (if you don't see it listed, check your Tools -> Addon Manager).  I created a wing with two segments, using the provided NACA 2412 airfoil.  The specifics are not terribly important; my goal was to get a mesh to compute and get the OpenFOAM solution to converge.

The CFD setup was straightforward:  steady-state, incompressible flow.  I created a 'Symmetry' constraint on the near wall.  The far, top and bottom walls had an inviscid constraint.  The flow went in the +X direction, and the appropriate faces constrained as Inlet and Outlet.  The wing surfaces all had a viscoud (no-slip) constraint.

Closeup of Mesh Refinement Around Wing
Mesh of the Domain and Wing Section
After wrapping the wing inside a calculation domain, and adding some mesh refinements near the wing surface, the grid appeared as shown.  Since my goal was only to get a valid solution, rather than the 'right' solution, I kept the mesh relatively course.​ The refinement around the wing was a bit excessive.  Also, in retrospect, the domain could have been reduced by about 50% vertically and along the wingspan.  But both the mesh and CFD calculations were fairly rapid.

​Taking the results into ParaView, I learned what the Clip filter does!  Then I added arrow glyphs to represent velocity.  I did not figure out how to avoid the short, stubby arrows, but that is a problem for future me. 

OpenFOAM Results In ParaView - Velocity Field
OpenFOAM Baby Steps - Calculating Lift and Drag (E...
OpenFOAM Baby Steps - 2D Flow Over a Cylinder

Related Posts

 

Comments

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Sunday, 27 September 2020

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