mass flow Inlet Guage pressure
 

I am trying to simulate flow through atomizing nozzle. Through which certain mass of pressurized air is passing for atomizing fuel.

For this should I put the value of

'Gauge pressure of atomizing air measured from a pressure transmitter'

in

Initial Gauge pressure field?

Known values:

mass flow rate = 0.1369 kg/s
temperature = 313 K
measured pressure = 9669950 Pa

Please also explain, when exactly we should give this initial gauge pressure value.