Hi users, I am modelling a 2D gas flow over a catalytic layer where steam reforming takes place. For getting the reactions in the catalyst I have written an UDF (3 global reactions with some kinetic parameters). The problem that I am facing is that sometimes I do not have any problems when I turned on the reaction and sometimes I run into the following error: Floating point error: invalid number. Any suggestion how to overcome that problem? Before I hooked on the UDF I have done some iterations until I got a stable flow in the reactor and I have lowered the URF for each species to 0.5.

Thanx for your help! Claud

try a different number type for your variables.(ie. int,real,float,double)