hi, i would like to ask about the setting of pressure in operating condition panel and the pressure in the initialize panel and the differance between them. secondly, is the pressure in fluent is set at the pressure gauge? thanks.

Real Static Pressure = Operating Pressure + Gauge Pressure

The operating pressure is a kind of "base pressure" which should be added to all "gauge pressures" to get the real pressure. Fluent performs all computations using the "gauge pressure". You should set the operating pressure to a value close to the average pressure in your domain - this minimizes round-off errors when Fluent computes pressure differences using the gauge pressure.