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-   -   error because of UDF or VOF ???? (http://www.cfd-online.com/Forums/fluent-udf/75282-error-because-udf-vof.html)

nishith April 21, 2010 06:23

error because of UDF or VOF ????
 
Hi i have used udf for creating a sinusoidal interface between two fluids for initializing the rayleigh taylor instability,

clarifying the situation

Its a rectangular domain in which i have defined two fluids( phases ), first one is acetone and another one is water. Now the high density fluid has been placed above the lower one and their interface has been defined in a sinusoidal pattern to trigger the rayleigh taylor instability


Problem faced

1. As i have used VOF scheme to define multi phase fluids, error is coming ( i.e. after few iterations i am getting a higher frequency wave imposed on the interface because the sinusoidal wave is defined by fine staircase) now how to rectify this error ????

2. I have got some information on the net in which by changing the function it self in udf ( by inserting epsilon in the function...etc) we can remove this imposition of higher frequency wave.... or we can smoothen the sinusoidal wave.... does any body having any idea about this functions.....??????

Please Reply

Regards,
Nishith


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