The Automatic Hydraulic Ram

Abstract

After describing the operation of a typical hydraulic ram installation, the paper reviews the fundamentals of the water hammer as a prerequisite to the proper understanding of the limitations of this hydraulic machine. The historical development is discussed in some detail with the object of ascertaining what research work remained to be done. The author presents his own theory based on the application of general laws of mechanics to the study of a specially designed experimental hydraulic ram. By means of a theory developed, which agrees satisfactorily with experiment, it is possible to forecast the behaviour of any automatic hydraulic ram, provided that the following four properties of a given installation have been determined separately by experiment: ( a) loss of head in the drive pipe; ( b) loss of head due to the impulse valve; ( c) drag coefficient of the impulse valve; and ( d) head lost during the period of retardation.