Acoustic resonances and blade vibration in axial flow compressors

Blade vibration in turbomachinery is a common problem that can lead to blade failure by high cycle fatigue. Although much research has been performed on axial flow turbomachinery, little has been published for radial flow machines such as centrifugal compressors and radial inflow turbines. This work develops a test rig that measures the resonant vibration of centrifugal compressor blades. The blade vibrations are caused by the wakes coming from the inlet guide vanes. These vibrations are measured using blade mounted strain gauges during a rotating test. The total damping of the blade response from the rotating test is compared to the damping from the modal testing performed on the impeller. The mode shapes of the response and possible effects of mistuning are also discussed. The results show that mistuning can affect the phase cancellation which one would expect to see on a system with perfect cyclic symmetry.

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Performance prediction of axial flow compressors using stage characteristics and simultaneous calculation of interstage parameters

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1243/0957650011536598 ◽

2001 ◽

Vol 215 (1) ◽

pp. 89-98 ◽

Cited By ~ 25

Author(s):

T. W. Song ◽

T. S. Kim ◽

J. H. Kim ◽

S. T. Ro

Keyword(s):

Gas Turbine ◽

System Analysis ◽

Axial Flow ◽

Performance Estimation ◽

Predicting Performance ◽

Functional Formulation ◽

Compressor Inlet ◽

Multistage Compressors ◽

And Performance ◽

Axial Flow Compressors

A new method for predicting performance of multistage axial flow compressors is proposed that utilizes stage performance curves. The method differs from the conventional sequential stage-stacking method in that it employs simultaneous calculation of all interstage variables (temperature, pressure and flow velocity). A consistent functional formulation of governing equations enables this simultaneous calculation. The method is found to be effective, i.e. fast and stable, in obtaining solutions for compressor inlet and outlet boundary conditions encountered in gas turbine analyses. Another advantage of the method is that the effect of changing the angles of movable stator vanes on the compressor's operating behaviour can be simulated easily. Accordingly, the proposed method is very suitable for complicated gas turbine system analysis. This paper presents the methodology and performance estimation results for various multistage compressors employing both fixed and variable vane setting angles. The effect of interstage air bleeding on compressor performance is also demonstrated.

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Axial Flow Compressors

Process Plant Machinery ◽

10.1016/b978-075067081-4/50015-7 ◽

1998 ◽

pp. 475-515

Keyword(s):

Axial Flow ◽

Axial Flow Compressors

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Axial-Flow Compressors, Pumps, and Fans

Turbomachinery ◽

10.1201/b16419-12 ◽

2013 ◽

pp. 127-168

Keyword(s):

Axial Flow ◽

Axial Flow Compressors

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Investigation on a Type of Flow Control to Weaken Unsteady Separated Flows by Unsteady Excitation in Axial Flow Compressors

Volume 5: Turbo Expo 2004, Parts A and B ◽

10.1115/gt2004-53167 ◽

2004 ◽

Cited By ~ 2

Author(s):

Xin-Qian Zheng ◽

Xiao-Bo Zhou ◽

Sheng Zhou

Keyword(s):

Wide Spectrum ◽

Excitation Frequency ◽

Axial Flow ◽

Maximum Velocity ◽

Excitation Amplitude ◽

High Order Scheme ◽

Wide Range ◽

Optimal Excitation ◽

Suction And Blowing ◽

Axial Flow Compressors

By solving unsteady Reynolds-averaged 2-D N-S equations discretized by a high-order scheme, the results showed that the disordered unsteady separated flow could be effectively controlled by periodic suction and blowing in a wide range of incidence, resulting in enhancement of time-averaged aerodynamic performances. The effects of unsteady excitation frequency, amplitude and excitation location were investigated in detail. The effective excitation frequency spans a wide spectrum and there is an optimal excitation frequency that is nearly equal to the Characteristic frequency of vortex shedding. Excitation amplitude exhibits a threshold value (nearly 10% in term of the ratio of maximum velocity of periodic suction and blowing to the velocity of free flow) and an optimal value (nearly 35%). The optimal excitation location is just upstream of the separation point. We also explored feasible unsteady actuators by utilizing upstream wake for constraining unsteady separation in axial flow compressors.

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