Transmission of Power by Sinusoidal Wave Motion through Hydraulic Oil in a Uniform Pipe

Abstract

An analysis is made of the viscous power losses in a liquid-filled pipe under oscillatory compressible flow conditions, particular attention being paid to Shell Tellus 27 oil in a 7/8 in diameter pipe, 80 ft long. Using an effective friction coefficient to take into account oscillating flow, the efficiency and the power-carrying capacity of the pipe are calculated for four discrete values of resistive output load. It is shown that if the load is not equal to the characteristic impedance of the pipe, then the efficiency is reduced and the power capacity depends upon the frequency of operation of the pipeline. A mismatched load should be resistive with the pipe preferably tuned to the quarter wavelength frequency supplied from a constant pressure generator. Relative power output increases under these conditions are achieved at the expense of efficiency and increased pipe pressure. Agreement between theory and experiment for the load conditions considered is good.