Effect of blade thickness on high frequency gust response

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

Turbomachinery rotor blades experience gust loading due to both inflow turbulence and circumferential variation in the mean velocity. The unsteady lift forces that result from these velocity disturbances can be a source of unwanted vibration and radiated noise. For incompressible flows, the blade gust response is often modeled using the well-known Sears function, which acts as a transfer function between a sinusoidal component of the gust and the fluctuating lift. However, the Sears function has a relatively slow high frequency roll-off and overpredicts the unsteady lift when the gust wavelength becomes much smaller than the blade chord. A more accurate model can be obtained by including the effect of blade thickness, which causes the gust to become distorted as it approaches the leading edge. This distortion results in attenuation of the higher-frequency components of the gust near the leading edge, which subsequently leads to reduced unsteady lift. In this paper, a model for the thickness effect is developed based on rapid distortion theory. Numerical calculations are made for a step-function gust encountering an elliptical leading edge with several thickness-to-chord ratios. The unsteady lift is calculated in the time domain, and a Fourier transform is used to obtain the frequency response. The results indicate that the gust response of a thick blade can be closely approximated by modifying the Sears function to include an exponential decay factor based on the thickness.

Original languageEnglish (US)
Title of host publicationAmerican Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA
Pages217-223
Number of pages7
DOIs
StatePublished - Dec 1 2005
Event2005 ASME International Mechanical Engineering Congress and Exposition, IMECE 2005 - Orlando, FL, United States
Duration: Nov 5 2005Nov 11 2005

Publication series

NameAmerican Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA
Volume32 NCA

Other

Other2005 ASME International Mechanical Engineering Congress and Exposition, IMECE 2005
CountryUnited States
CityOrlando, FL
Period11/5/0511/11/05

Fingerprint

gusts
blades
Turbomachine blades
leading edges
Turbomachinery
Incompressible flow
rotor blades (turbomachinery)
Frequency response
Transfer functions
Fourier transforms
Turbulence
Rotors
step functions
incompressible flow
Wavelength
transfer functions
frequency response
disturbances
attenuation
turbulence

All Science Journal Classification (ASJC) codes

  • Mechanical Engineering
  • Acoustics and Ultrasonics

Cite this

Lysak, P. D. (2005). Effect of blade thickness on high frequency gust response. In American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA (pp. 217-223). (American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA; Vol. 32 NCA). https://doi.org/10.1115/IMECE2005-80006
Lysak, Peter Daniel. / Effect of blade thickness on high frequency gust response. American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA. 2005. pp. 217-223 (American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA).
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Lysak, PD 2005, Effect of blade thickness on high frequency gust response. in American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA. American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA, vol. 32 NCA, pp. 217-223, 2005 ASME International Mechanical Engineering Congress and Exposition, IMECE 2005, Orlando, FL, United States, 11/5/05. https://doi.org/10.1115/IMECE2005-80006

Effect of blade thickness on high frequency gust response. / Lysak, Peter Daniel.

American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA. 2005. p. 217-223 (American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA; Vol. 32 NCA).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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Lysak PD. Effect of blade thickness on high frequency gust response. In American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA. 2005. p. 217-223. (American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA). https://doi.org/10.1115/IMECE2005-80006