The Acoustic Experimental Investigation of Counterrotating Propeller Configurations

An experimental study of scale conterrotating propellers operating in an anechoic facility have been conducted. Various configurations of counterrotation for equal numbers of blades per disk have been tested along with single rotation propellers underscoring the fundamental acoustic differences between single and counterrotation propeller operation. In addition, it is shown that as the loading on the counterrotating system is increased the OASPL is also increased in both the disk plane and axial direction.