query on the EFFDEF expert

john

I mean the Expert Parameter in the Euranus Interface. The Manual Tells the Default value is 1, which means the definition for pump within incompressble flow is DELTA-P0 / QM / OMEGA / TORQUE (the So-Called £Ô£Ï£Ô£Á£Ì¡¡£Ô£Ï¡¡£Ô£Ï£Ô£Á£Ì). and the value 2 definites the efficiency by the so-called £Ô£Ï£Ô£Á£Ì¡¡£Ô£Ï¡¡£Ó£Ô£Á£Ô£É£Ã. As for me, I am not expert in fluid dynamic. can anybody tell me which value should I make it?-----I am dealing with a water pump. thank you .