it's just the result of the volume integral of UDM5. The result that i have got in the serial case is the expected result when i use analytical equations to calculate the mass deposited it exactly matches the result from serial case. The only change that i did in the parallel case is increase the number of processor from 1 to 4. to see if my mass deposited matches. turns out it does not. 

The reason is that the UDF needs to be parallelized.

When i start looking at what UDFs need to be parallelized the first question i encounter is- do i need to parallelize the scalar update udf? that leads me to my question where should i put # if RP_HOST? in scalar update UDF