The effects of inlet conditions on supersonic cascade noise

✍ Scribed by D.L. Hawkings

• Publisher: Elsevier Science
• Year: 1974
• Tongue: English
• Weight: 865 KB
• Volume: 33
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1016/s0022-460x(74)80007-6

✦ Synopsis

A theory is presented describing the generation of noise by supersonic cascades with non-uniform inlet ducts. The analysis is based upon a quasi-two-dimensional model, and allows for a slow variation of duct cross-sectional area and axial velocity upstream of the blades. The technique used is a combination of geometric acoustics and weak shock theory. It is shown that the upstream acoustic field depends primarily upon a single age parameter which is defined by a simple integral of the duct area and velocity distributions. The general implications for minimising the noise output are explained, and two numerical examples are also given.