# POLYFLOW - How can I calculate the relative die balancing?

 Is it possible to quantify the die balancing by means of a function that varies between 0 and 1?The die balancing function defined in POLYFLOW is given byhttp://www.fluentusers.com/support/solutions/1300/absolute_die_balance.gifhttp://www.fluentusers.com/support/solutions/1300/absolute_die_balance.gifwhere v.n = normal velocity, Q = flow rate and A = area of outlet section.For a perfectly balanced flow, the velocity is spatially uniform and the value of the die balancing function becomes zero. In general, an optimal flow balance can be achived by minimizing the value of the die balancing function. The die balancing function is dimensional and depends on flow rate and the area of the outlet section.The relative die balancing function is defined ashttp://www.fluentusers.com/support/solutions/1300/relative_die_balance.gifhttp://www.fluentusers.com/support/solutions/1300/relative_die_balance.gifwhere A = area of outlet section , Vn = normal velocity, Vav = Q/A, Q = flow rate. The obtained result is dimensionless, and equals 0 for a perfectly balanced velocity field. Although the result is dimensionless, it is important to note that the calculated quantity is not bounded: it is indeed possible to derive a velocity distribution that verifies the assigned flow rate, and which exhibits a die balancing value significantly larger than 1.The use of the relative die balancing function instead of the normal die balancing function can be enabled via the RELATIVE_BALANCE_FUNCTIONkeyword in the .p3rc file. As this keyword impacts POLYDATA, an existing data file must be reloaded in POLYDATA and saved again. A run of POLYFLOW with the new data file will produce the expected results.