On the prediction of downsurge in pump systems.

A general prediction analysis with special emphasis on downsurges. The graphical results are correlated with the findings based on an analytical method. It is shown that in the case of negligible inertia, the graphical method becomes more handy and reliable than the analytical method which used finite difference techniques. The existence of a critical inertia below which there is no flywheel effect has been confirmed by both methods. Non dimensional flywheel number has proved its effectiveness in making the prediction charts simple and also in expressing the flywheel effect separately was conducted.