An Analytical Relationship Between Compressor Thermofluid Efficiency and Manifold Acoustic Modes

Basic thermofluid processes of a positive displacement compressor are strongly dependent upon the acoustic behavior of the manifolds. Hence manifold tuning is very important so as to increase flow capacity while reducing energy consumption and fluidborne noise; recently we developed a computer simulation program used to examine the tuning phenomena analytically. However, such numerical predictions may not lead directly to either a physical understanding of the tuning phenomena or to simple analytical expressions which could be used by a designer for finding the most suitable solution. This paper presents a hypothesis that relates in general functional form the flow and energy efficiencies and pressure pulsations of a compressor to the acoustic modes of the manifolds. Application is demonstrated through the example case of a two-cylinder compressor suction manifold. The results of the linear system study undertaken here match well with the predictions of the computer simulation program and experiment. The hypothesis set forth in this paper should lead future investigators to develop the important relationships between compressor performance and manifold design.