subcooled boiling flow
 

Hi guys
I want to simulate subcooled boiling flow in vertical tube. my UDF codes in a simple vertical tube worked very well. but in another tube with different geometery and mesh isnot worked. output of my UDF codes in new geometery have true value but fluent then 3 iterate show this errors:
Floating point error-invalid number
or
1#QNB.
please help me to solution this problem.