SimCafe

Space shortcuts

Child pages
  • User Defined Functions - Numerical Solution

Versions Compared

Old Version 15

changes.mady.by.user user-64ddb

Saved on

compared with

New Version 16

changes.mady.by.user user-64ddb

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.
Comment: Migration of unmigrated content due to installation of a new plugin
Include Page
FLUENT Google Analytics
FLUENT Google Analytics
Include Page
User Defined Functions - Panel
User Defined Functions - Panel

Numerical Solution

The strategy for computing the lift force using the UDF is as follows:

1. Turn on a 'user defined scaler' φ which Fluent will solve for
2. On the cylinder surface, set the below equation by implementing the UDF as a boundary condition for φ 

Wiki Markup
{latex}\begin{eqnarray}
\phi = -psin(\theta)
\end{eqnarray}{latex}

3. Run at least one iteration to integrate φ over the cylinder surface

Note that the liftFunc UDF calculates a side force that is NOT normalized. So you'll have to divide the reported value by 0.5*rho*v^2*D*1 to get the normalized side force. This is because when you integrate liftFunc, you get the integral of -p*sin(theta) on the chosen surfaces.

User-defined function implementation to obtain the lift coefficient around the cylinder is as follows.

HTML
<iframe width="600" height="338" src="//www.youtube.com/embed/RZAvenIhH_s?list=UU8bXUXdcNDyFTIp6YVrtReg" frameborder="0" allowfullscreen></iframe>


Go to Step 6: Numerical Results
Go to all FLUENT Learning Modules