The analyses of transient responses of fluid lines by characteristics grid method.

An approach is made for the analyses of the transient responses of pneumatic and oil pipe lines. The algorithm based on the characteristics grid method considers the variations of the density, pulse wave speed and kinematic viscosity of the fluids due to the pressure changes in pipes. The numerical results are compared with the experimental results or the ones ob t ained by other analyticalm ethods for problems of this type and discussed to obtain the following conclusions: The approach is effective in predicting the transient responses of pneumatic pipe line. And also, in oil pipe lines, it obtains excellent results inclusive of the severe pressure changes due to high-pressureo peration of the directional control valve.