Use of Experimentally Determined Acoustic Impedance in Analysis of Propulsion System Stability

Abstract

As indicated in Fig. 1, the concept of acoustic impedance has been used for many years in a variety of engineering problems including development of loud speakers and public address systems. It is shown (Fig. 2) that this concept can be borrowed from acoustics, generalized to include the effect of flow rate and real fluid effects such as boundary layers and shock boundary layer interactions, and applied as in Fig. 3 in the rational analysis of propulsion system transient properties.