Noise caused by the interaction of a rotor with anisotropic turbulence

Edward J Kerschen, P. R. Gliebe

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

An analytical model of fan noise caused by inflow turbulence, a generalization of earlier work by Mani, is presented. Axisymmetric turbulence theory is used to develop a statistical representation of the inflow turbulence valid for a wide range of turbulence properties. Both the dipole source due to rotor blade unsteady forces and the quadrupole source resulting from the interaction of the turbulence with the rotor potential field are considered. The effects of variations in turbulence properties and fan operating conditions are evaluated. For turbulence axial integral length scales much larger than the blade spacing, the spectrum is shown to consist of sharp peaks at the blade passing frequency and its harmonics, with negligible broadband content. The analysis can then be simplified considerably and the total sound power contained within each spectrum peak becomes independent of axial length scale, while the width of the peak is inversely proportional to this parameter. Large axial length scales are characteristic of static fan test facilities, where the transverse contraction of the inlet flow produces highly anisotropic turbulence. In this situation, the rotor/turbulence interaction noise is caused mainly by the transverse component of turbulent velocity.

Original languageEnglish (US)
Pages (from-to)717-723
Number of pages7
JournalAIAA Journal
Volume19
Issue number6
DOIs
StatePublished - 1981
Externally publishedYes

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Turbulence
Rotors
Fans
Inlet flow
Test facilities
Turbomachine blades
Analytical models
Acoustic waves

ASJC Scopus subject areas

  • Aerospace Engineering

Cite this

Noise caused by the interaction of a rotor with anisotropic turbulence. / Kerschen, Edward J; Gliebe, P. R.

In: AIAA Journal, Vol. 19, No. 6, 1981, p. 717-723.

Research output: Contribution to journalArticle

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