Hi sorry I Can't seem to edit the original post it was meant to be:

Hi All,

I have written a UDF that works perfectly on my laptop. There are several messages and output files built into so that I know if it is working.

When I put this onto the HPC cluster I get a message in my consol and output in my file for every single node. the result for all but one is NaN. This is making quite difficult to understand the results. 

I was wondering if anyone knew a solution to this.

Here is the sample of my udf code responsible for this:

 FILE *fp = NULL;

 char filename[20];

 sprintf(filename, "NoNacelleOutput_%gms.txt", Uin);

 Message("%s ", filename);

 Message("%g ", Uin);

 fp = fopen(filename, "a");

 fprintf(fp, "Itteration %i [m^2]\n", N_ITER);

 fprintf(fp, "Area of the actuator disk = %g [m^2]\n", Area);

 fprintf(fp, "Absolute Area-Weighted Average Velocity Over the Disk %g [ms^-1]\n", U);

 fprintf(fp, "Value of the Normalizer = %g\n", Normalizer);

 fprintf(fp, "Total thrust fromt the disk = %g [N]\n", T);

 fprintf(fp, "Input thrust = %g [N]\n \n", thrust);