Induction Ramming of Small High-Speed Air Compressor

Abstract

The paper describes an investigation of the effects of piston-excited pressure waves in the plain induction pipe of a small, high-speed, single-cylinder air compressor. For a range of pipe lengths and diameters, compressor speeds and delivery pressures, the observed compressor throughput and driving torque are compared with those obtained with no intake pipe fitted. Based on classical laws of wave motion but using an experimentally obtained steady-flow characteristic for the inlet valve, a theoretical treatment is developed to describe the pressure pulsations in the inlet port and cylinder and to predict the change in airflow resulting from the fitting of any particular intake pipe. Experimentally recorded indicator diagrams compare satisfactorily with those predicted theoretically and similar agreement is obtained between the experimental and theoretical values of airflow. An 18 per cent increase in airflow is reported.