Rotating Stall Induced Non-Synchronous Blade Vibration Analysis for an Unshrouded Industrial Centrifugal Compressor

Zhao, Xinwei; Zhou, Qiang; Yang, Shuhua; Li, Hongkun

doi:10.3390/s19224995

Cited by 23 publications

(19 citation statements)

References 26 publications

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“…This kind of a coarse measurement, known as Zablotskiy method [42], should, therefore, be used only as a first approximation, while reliable synchronous vibration measurement requires a multi-sensor system. This is extremely important as viewing displacement plots for blades provides very little information but is often considered by engineers as an essential tool e.g., [3,43,44].…”

Section: Eo2 Forced Responsementioning

confidence: 99%

“…Non-contact blade vibration measurement, known as blade tip-timing (BTT) or Non-Intrusive Stress Measurement System (NSMS), is a technique for determining dynamic blade stresses to ensure the structural integrity of bladed disks in jet engines and stationary turbines [1,2]. It can be used in axial or radial compressors [3] and unshrouded or shrouded turbines [4]. The method uses several sensors mounted circumferentially to precisely determine temporary positions of each blade tip in every rotation [5].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Non-Contact Measurement of Blade Vibration in an Axial Compressor

Przysowa

Russhard²

2019

Sensors

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Complex blade responses such as a rotating stall or simultaneous resonances are common in modern engines and their observation can be a challenge even for state-of-the-art tip-timing systems and trained operators. This paper analyses forced vibrations of axial compressor blades, measured during the bench tests of the SO-3 turbojet. In relation to earlier studies conducted in Poland with a small number of sensors, a multichannel tip-timing system let us observe simultaneous responses or higher-order modes. To find possible symptoms of a failure, blade responses in a healthy and unhealthy engine configuration with an inlet blocker were studied. The used analysis methods covered all-blade spectrum and the circumferential fitting of blade deflections to the harmonic oscillator model. The Pearson coefficient of correlation between the measured and predicted tip deflection is calculated to evaluate fitting results. It helps to avoid common operator mistakes and misinterpreting the results. The proposed modal solver can track the vibration frequency and adjust the engine order on the fly. That way, synchronous and asynchronous vibrations are observed and analysed together with an extended variant of least squares. This approach saves a lot of work related to configuring the conventional tip-timing solver.

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Section: Eo2 Forced Responsementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Non-Contact Measurement of Blade Vibration in an Axial Compressor

Przysowa

Russhard²

2019

Sensors

View full text Add to dashboard Cite

show abstract

“…This is extremely important as viewing displacement plots for blades provides very little information but is often considered by engineers as an essential tool e.g. [3,41,42].…”

Section: Eo2 Forced Responsementioning

confidence: 99%

“…Non-contact blade vibration measurement, known as Blade Tip-Timing (BTT) or Non-contact Stress Measurement System (NSMS), is a technique for determining dynamic blade stresses to ensure the structural integrity of bladed disks in jet engines and stationary turbines [1,2]. It can be used in axial or radial compressors [3] and unshrouded or shrouded turbines [4]. The method uses several sensors mounted circumferentially to precisely determine temporary positions of each blade tip in every rotation [5].…”

Section: Introductionmentioning

confidence: 99%

Non-Contact Measurement of Blade Vibration in an Axial Compressor

Przysowa¹,

Russhard²

2019

Preprint

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Complex blade responses such as a rotating stall or simultaneous resonances are common in modern engines and their observation can be a challenge even for state-of-the-art tip-timing systems and trained operators. This paper analyses forced vibrations of axial compressor blades, measured during the bench tests of the SO-3 turbojet. In relation to earlier studies conducted in ITWL with a small number of sensors, a multichannel tip-timing system let us observe simultaneous responses or higher-order modes. To find possible symptoms of a failure, blade responses in a healthy and unhealthy engine configuration with an inlet blocker were studied. The used analysis methods covered all-blade spectrum and the circumferential fitting of blade deflections to the harmonic oscillator model. The proposed modal solver can track the vibration frequency and adjust the engine order on the fly. That way, synchronous and asynchronous vibrations are observed and analysed together with an extended variant of least squares. The proposed approach helps to avoid common mistakes and saves a lot of work related to configuring the conventional solver.

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“…By analyzing the development process of tip flow blockage, the oscillation of separated flow blockage at the rotor tip region is considered as an important factor for the aeroelastic stability of the compressor. The tip-timing measurements analysis for non-synchronous vibration are presented in [ 23 , 24 , 25 ], and provide information for understanding the blade vibrating behaviors. This NSV phenomenon become a major interest for acoustic investigations yet, with establishing an analytical sound model [ 26 ].…”

Section: Introductionmentioning

confidence: 99%

Investigation on the Flow Field Entropy Structure of Non-Synchronous Blade Vibration in an Axial Turbocompressor

Zhang

Hou

2020

Entropy

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In order to explore the inducing factors and mechanism of the non-synchronous vibration, the flow field structure and its formation mechanism in the non-synchronous vibration state of a high speed turbocompressor are discussed in this paper, based on the fluid–structure interaction method. The predicted frequencies fBV (4.4EO), fAR (9.6EO) in the field have a good correspondence with the experimental data, which verify the reliability and accuracy of the numerical method. The results indicate that, under a deviation in the adjustment of inlet guide vane (IGV), the disturbances of pressure in the tip diffuse upstream and downstream, and maintain the corresponding relationship with the non-synchronous vibration frequency of the blade. An instability flow that developed at the tip region of 90% span emerged due to interactions among the incoming main flow, the axial separation backflow, and the tip leakage vortices. The separation vortices in the blade passage mixed up with the tip leakage flow reverse at the trailing edge of blade tip, presenting a spiral vortex structure which flows upstream to the leading edge of the adjacent blade. The disturbances of the spiral vortexes emerge to rotate at 54.5% of the rotor speed in the same rotating direction as a modal oscillation. The blade vibration in the turbocompressor is found to be related to the unsteadiness of the tip flow. The large pressure oscillation caused by the movement of the spiral vortex is regarded as the one of the main drivers for the non-synchronous vibration for the present turbocompressor, besides the deviation in the adjustment of IGV.

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Rotating Stall Induced Non-Synchronous Blade Vibration Analysis for an Unshrouded Industrial Centrifugal Compressor

Cited by 23 publications

References 26 publications

Non-Contact Measurement of Blade Vibration in an Axial Compressor

Non-Contact Measurement of Blade Vibration in an Axial Compressor

Non-Contact Measurement of Blade Vibration in an Axial Compressor

Investigation on the Flow Field Entropy Structure of Non-Synchronous Blade Vibration in an Axial Turbocompressor

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