FLUENT - Using the profile file generated with the In-Cylinder model for other deforming mesh applications


With the In-Cylinder model in FLUENT, a profile file can be written out that describes the In-Cylinder motion. This file can then be modified to accomodate the mesh motion for other deforming mesh applications that cannot be solved with the standard In-Cylinder model. One example of such an application is where the calculation domain includes multiple pistons with the initial position of each piston being at a different crank angle. The motion of each piston requires its own independent profile which cannot be handled by the standard In-Cylinder model in FLUENT. This solution demonstrates a method to solve such an application by writing out the profile file with the In-Cylinder model and then modifying it to generate the independent profiles required to describe the motion of each piston.

It is possible to write out the profile file of piston-full, using the following instructions:

Using the Text User Interface (TUI) on the FLUENT console window, type:

/define/models/dynamic-mesh-controls/in-cylinder-parameter

Next, type ppl to invoke the print-plot-lift text command.
Enter **piston-full**.
Click return twice.
Enter a start angle of 0 degrees.
Enter an end angle of 720 degrees.
Enter an increment of 10 degrees.
Plot Lift? no

FLUENT will print time, lift and angle data on the console
time=0.00, lift=0.0, (angle=0.0)
..
..

All these lines can then be copied and pasted into a text file.
Then convert the time lift data into a tabular format as shown in following link:http://www.fluentusers.com/fluent/doc/ori/html/ug/node176.htm#26465

Instead of lift, the x, y or z coordinate can be used, depending on the direction in which piston needs to be moved.





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Comments
 
when i enter the code (define/models/dynamic-mesh-controls/in-cylinder-parame ter)and pressing the enter it comes invalid commands[-define]
could you please guide?
Farzad Montazery, Sat Nov 22, 2014