The Use of Gases Other Than Air in the Acoustical Testing of Model Compressors Free

Studies were made of the feasibility of simulating acoustical and aerodynamic characteristics of a full-scale axial-flow air compressor with a scale model operating in Freon in a closed-loop system. Correlation was attained between model and prototype for both acoustical and aerodynamic performance. Agreement was obtained with a previously published generalized acoustic prediction curve; and a tentative acoustic scaling law was developed which permits rapid prediction of full-scale sound power levels from measurements of the sound power levels produced by a model.