Investigation of Tonal Noise in a High Pressure Turbine Stage Due to Temperature Inhomogeneous of the Inflow

Mu Zhongqiang,Qiao Weiyang,Ulf Michel

doi:10.5539/mas.v6n6p64

Mu Zhongqiang, Qiao Weiyang + Show 1 more

Open Access

https://doi.org/10.5539/mas.v6n6p64

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Abstract

The tonal sound emission of a high pressure turbine stage due to total temperature inhomogeneous of the inflow investigated numerically. A non-uniform mean temperature made by a result of the discrete burners inside the annular combustion chamber. In present paper we made a setting that 14 periodic total temperature distribution in the azimuthal direction in the turbine inlet. Through comparison between non-uniform inlet temperature case and uniform inlet temperature case, the results show that the sound power emitted in the downstream direction is increased by 5.9 dB at the blade-passing frequency and by remarkably 11.6 dB at the first harmonic of the blade-passing frequency. This result indicated the total temperature fluctuation in the inlet of turbine stage would affect the sound field drastically.

Highlights

The success in reducing jet noise and fan noise result in core noise becoming relatively more and more important in modern engine
Indirect combustion noise is generated in the nozzle guide vanes at the exits of combustors and in the following turbine stages as a result of the unsteadiness of the fluid temperature (Cumpsty & Marble, 1977; 1979)
The circumferential mode due to the effect of rotor-stator interaction and periodic total temperature-rotor interaction is obviously, and the amplitude of fluctuation pressure is bigger in non-uniform temperature inlet case

Summary

Introduction

The success in reducing jet noise and fan noise result in core noise becoming relatively more and more important in modern engine. Combustors contribute substantially to the tonal noise that is emitted from the core nozzle of a turbofan engine. This contribution can be separated into direct and indirect combustion noise. Indirect combustion noise is generated in the nozzle guide vanes at the exits of combustors and in the following turbine stages as a result of the unsteadiness of the fluid temperature (Cumpsty & Marble, 1977; 1979). Some scientists have done some studies on indirect combustion noise. Bake et al (2007; 2008; 2009) has demonstrated the indirect combustion noise by using a electrically heated flow as a inlet flow for a convergent-divergent nozzle tube. A numerical simulation of this simple experimental setup was performed by Leykoa et al (2009)

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