Abstract:Viscous flow equations for two-dimension were transformed into frequency characteristics formulae. Numerical prediction method, simulation model and application software have been used for calculating the dynamic characteristics (gain, phase, resonance angular frequency and maximal amplitude ratio, etc.) of pulsating flow in branch in the hydraulic servo systems, which can make the numerical prediction with digital computer highly effective and accurate. A new inspection method for hydraulic system was also provided.

Key words: viscous flow　numerical prediction　pulsating flow　hydraulic servo system