INVESTIGATION ON MODE CHARACTERISTICS OF ROTATING INSTABILITY AND ROTATING STALL IN AN AXIAL COMPRESSOR

2021 ◽  
pp. 1-24
Author(s):  
Zeyuan Yang ◽  
Yadong Wu ◽  
Hua Ouyang
Keyword(s):  
Axial Compressor ◽  
Calibration Method ◽  
Acoustic Mode ◽  
Rotating Stall ◽  
Frequency Spectra ◽  
Compressor Rotor ◽  
Mode Decomposition ◽  
Aerodynamic Instability ◽  
Rotating Instability ◽  
Mode Order

Abstract Rotating instability (RI) and rotating stall (RS) are two types of aerodynamic instability in axial compressors. The former features the side-by-side peaks below the blade passing frequency (BPF) in frequency spectra, and the latter represents one or more stall cells rotating in the compressor. This paper presents an experimental on the nearfield pressure and farfield acoustic characteristics of RI phenomenon in a low-speed axial compressor rotor, which endures both RI and RS at several working conditions. In order to obtain the high-order modes of RI and other aerodynamic instability, a total of 9 or 20 Kulites are circumferentially mounted on the casing wall to measure the nearfield pressure fluctuation using a mode order calibration method. Meantime in the farfield 16 microphones are planted to measure the acoustic mode order using the compressive sensing method. Through calibration the experiments acquire the mode orders generated by RI and the interaction between RI and BPF, which is higher than the number of transducers. As for RS, the mode decomposition shows a mode order of 1, indicating one single stall cell rotating in the compressor. This experiment also shows that amplitude of RI modes is decreased when RS occurs, but RS modes and RI modes will both be enhanced if the flow rate is further reduced. This experiment reveals that RI experiences three stages of “strengthen-weaken-strengthen”, and hence RI may not be regarded only as “prestall” disturbance.

Investigation on Mode Characteristics of Rotating Instability and Rotating Stall in an Axial Compressor

2021 ◽  
Author(s):  
Zeyuan Yang ◽  
Yadong Wu ◽  
Hua Ouyang
Keyword(s):  
Axial Compressor ◽  
Calibration Method ◽  
Acoustic Mode ◽  
Rotating Stall ◽  
Frequency Spectra ◽  
Compressor Rotor ◽  
Mode Decomposition ◽  
Aerodynamic Instability ◽  
Rotating Instability ◽  
Mode Order

Abstract Rotating instability (RI) and rotating stall (RS) are two types of aerodynamic instability in axial compressors. The former features the side-by-side peaks below the blade passing frequency (BPF) in frequency spectra, and the latter represents one or more stall cells rotating in the compressor. This paper presents an experimental on the nearfield pressure and farfield acoustic characteristics of RI phenomenon in a low-speed axial compressor rotor, which endures both RI and RS at several working conditions. In order to obtain the high-order modes of RI and other aerodynamic instability, a total of 9 or 20 Kulites are circumferentially mounted on the casing wall to measure the nearfield pressure fluctuation using a mode order calibration method. Meantime in the farfield 16 microphones are planted to measure the acoustic mode order using the compressive sensing method. Through calibration the experiments acquire the mode orders generated by RI and the interaction between RI and BPF, which is higher than the number of transducers. As for RS, the mode decomposition shows a mode order of 1, indicating one single stall cell rotating in the compressor. This experiment also shows that amplitude of RI modes is decreased when RS occurs, but RS modes and RI modes will both be enhanced if the flow rate is further reduced. This experiment reveals that RI experiences three stages of “strengthen-weaken-strengthen”, and hence RI may not be regarded only as “prestall” disturbance.

Origins and Structure of Rotating Instability: Part 1 — Experimental and Numerical Observations in a Subsonic Axial Compressor Rotor

2016 ◽  
Author(s):  
Yanhui Wu ◽  
Zhiyang Chen ◽  
Guangyao An ◽  
Jun Liu ◽  
Guowei Yang
Keyword(s):  
Axial Compressor ◽  
Stability Limit ◽  
Periodic Oscillation ◽  
Tip Leakage ◽  
Flow Unsteadiness ◽  
Compressor Rotor ◽  
Clearance Flow ◽  
The Stability ◽  
Rotating Instability ◽  
Mode Order

Rotating instability (RI) is an obvious unsteady flow phenomenon occurring in the tip region of compressors, which is potentially linked to tip clearance flow noise, blade vibration and rotating stall/surge. The existing investigations for RI indicate the origins of RI are closely related to unsteady flow behaviors in given blade passages in the rotating reference frame, which depend on the design specifics of axial machines. However, no efforts are made to set up a quantitative link between the time scale of unsteady behavior in a given passage and the characteristic parameters of RI, let alone to define the fluid dynamic processes/events which are causally linked with the RI inception. This is the motivation for the current investigations. In Part I, the experimental and numerical investigations are carried out to investigate tip flow unsteadiness in a subsonic axial compressor rotor. The measurement results show RI appears at operating points near the stability limit of the test rotor. It becomes more pronounced with mass flow rate decreased. The corresponding computational experiments show that flow unsteadiness in given passages also appears close to the stability limit with its initial origination confined to the tip region. The appearance of tip flow unsteadiness is accompanied by a phase lag pattern in different passages across the circumference similar to the detection of stall flutter. The well-developed Fourier-decomposed method is thus used to evaluate the mode characteristics of circumferential traveling waves. It turns out the circumferential traveling wave rotating against the rotor rotation direction with the mode order of 4 is prominent in the flow field with its frequency in the absolute frame equivalent to the mean frequency value of RI detected in measurements. The further analyses of the simulated flow fields indicate that tip flow unsteadiness in a given passage attributes to the periodic oscillation of “secondary clearance flow”, which induces a blockage tranfer across the passage. The mode order and propagation speed of RI depend on the blockage transfer induced by the periodic oscillation of “secondary clearance flow” between two neighbouring passages along the whole circumference. The investigation results presented in the paper implies that one of early ideas to interpret the origin of RI might be altered to such an extent that it contains any unsteady behavior associated with tip leakage flow, rather than limited to “periodical oscillation of tip leakage vortex”.

Numerical Investigation of Relation Between Unsteady Behavior of Tip Leakage Vortex and Rotating Disturbance in a Transonic Axial Compressor Rotor

2008 ◽  
Author(s):  
K. Yamada ◽  
K. Funazaki ◽  
H. Sasaki
Keyword(s):  
Vortex Breakdown ◽  
Axial Compressor ◽  
Tip Clearance ◽  
Tip Leakage Vortex ◽  
Tip Clearance Flow ◽  
Tip Leakage ◽  
Compressor Rotor ◽  
Clearance Flow ◽  
Transonic Axial Compressor ◽  
Rotating Instability

The purpose of this study is to have a better understanding of the unsteady behavior of tip clearance flow at near-stall condition from a multi-passage simulation and to clarify the relation between such unsteadiness and rotating disturbance. This study is motivated by the following concern. A single passage simulation has revealed the occurrence of the tip leakage vortex breakdown at near-stall condition in a transonic axial compressor rotor, leading to the unsteadiness of the tip clearance flow field in the rotor passage. These unsteady flow phenomena were similar to those in the rotating instability, which is classified in one of the rotating disturbances. In other words it is possible that the tip leakage vortex breakdown produces a rotating disturbance such as the rotating instability. Three-dimensional unsteady RANS calculation was conducted to simulate the rotating disturbance in a transonic axial compressor rotor (NASA Rotor 37). The four-passage simulation was performed so as to capture a short length scale disturbance like the rotating instability and the spike-type stall inception. The simulation demonstrated that the unsteadiness of tip leakage vortex, which was derived from the vortex breakdown at near-stall condition, invoked the rotating disturbance in the rotor, which is similar to the rotating instability.

Dynamic Total Head Loss Characteristic for an Axial Compressor Rotor

1980 ◽  
Vol 22 (6) ◽  
pp. 269-276 ◽  
Author(s):  
P. B. Sharma ◽  
J. W. Railly
Keyword(s):  
Time Delay ◽  
Time Lag ◽  
Axial Compressor ◽  
Numerical Procedure ◽  
Head Loss ◽  
Rotating Stall ◽  
Phase Lock ◽  
Compressor Rotor ◽  
Total Head ◽  
Loss Characteristic

Detailed flow field and pressure measurements during rotating stall operation have been carried out at inlet to and exit from an axial compressor rotor using hot wire anemometers and probes incorporating fast response pressure transducers. An on-line data-acquisition system which employs a phase-lock sampling and averaging technique has been used to obtain ‘phase-lock averaged’ values of flow quantities and pressures. The dynamic total head loss/incidence characteristic for the rotor section at mean diameter has been computed from the above data. The dynamic characteristic exhibits a loop in the stalled region. A simple numerical procedure has been used to obtain the steady-state loss characteristic and the time-lag of this loss. It has been found that the loss time-lag of boundary layer time delay corresponds to a value equal to 1.8 times the time delay due to inertia of fluid in a blade passage. A simple theory for the prediction of this loss time-lag is also presented which shows reasonable agreement with the value determined from measurements.

scholarly journals Active flow control at a 1.5-stage low-speed research compressor with varying rotor tip clearance

2011 ◽  
Vol 225 (7) ◽  
pp. 886-896 ◽  
Author(s):  
M Künzelmann ◽  
R Urban ◽  
R Mailach ◽  
K Vogeler
Keyword(s):  
Flow Control ◽  
Active Flow Control ◽  
Axial Compressor ◽  
Rotating Stall ◽  
Tip Clearance ◽  
Stall Inception ◽  
Low Speed ◽  
Operating Range ◽  
Compressor Rotor ◽  
Active Flow

The stable operating range of axial compressors is limited by the onset of rotating stall and surge. Mass injection upstream of the tip of an axial compressor rotor is a stability enhancement approach which can be effective in suppressing stall in tip-critical rotors, and thus increasing the operating range of compressors. In this article, investigations on active flow control related to the rotor tip gap sensitivity are discussed. The experiments were performed in a 1.5-stage low-speed research compressor. Measurements at part speed (80 per cent) and full speed (100 per cent) with varying injection rates are discussed. These tests were performed for two rotor tip clearances of 1.3 per cent and 4.3 per cent of rotor blade tip chord. Results on the compressor map, the flow field as well as transient measurements to identify the stall inception are discussed. Supplementary, the numerical results are compared to the experiments based on the configuration with the greatest benefit in operating range enhancement.

scholarly journals Relative Flow Structure at Exit From an Axial Compressor Rotor in Rotating Stall

1984 ◽  
Author(s):  
R. Cheng ◽  
H. Ekerol ◽  
J. W. Railly
Keyword(s):  
Reverse Flow ◽  
Cell Structure ◽  
Axial Compressor ◽  
Orientation Angle ◽  
Rotating Stall ◽  
Compressor Rotor ◽  
Flow Vector ◽  
Trailing Edges ◽  
Probe Orientation

The phase-lock-averaging (PLA) technique is used in association with a traverse gear mounted on an axial compressor rotor to explore the flow field at exit from the rotor during rotating stall. The technique requires the use of a trigger hot-wire anemometer also mounted on the rotor to ensure the proper location of the stall cell in relation to the measurement probe. The probe consists of a three-wire non-orthogonal array which may be traversed radially and peripherally over a complete blade passage. By a systematic adjustment of the probe orientation angle, the presence of reverse flow is detected. A mathematical procedure for the determination of the magnitude and direction of the flow vector is presented. On the basis of a large collection of phase-locked data it is demonstrated that the leading and trailing edges of the cell travel at a non-uniform rate and in such a way as to vary cyclically in peripheral extent with a period related to the blade passing fequency. The peripheral distribution of the flow vector at successive instants of relative time is also produced from the data collection and the evolution of the stall cell structure is presented.

Analysis of Rotating Stall Inception in an Axial Compressor Rotor Using EFD and CFD

2003 ◽  
Vol 2003 (0) ◽  
pp. 72
Author(s):  
Isao TOMITA ◽  
Masato FURUKAWA ◽  
Takahiro MINAMI ◽  
Kazutoyo YAMADA ◽  
Masahiro INOUE
Keyword(s):  
Axial Compressor ◽  
Rotating Stall ◽  
Stall Inception ◽  
Compressor Rotor

Wavelet-Analysis of Rotating Stall Development in an Axial Compressor Rotor

2000 ◽  
Vol 2000.4 (0) ◽  
pp. 59-60
Author(s):  
Motoo KUROUMARU ◽  
Tadakazu TANINO ◽  
Shinnichi YOSHIDA ◽  
Masahiro INOUE ◽  
Masato FURUKAWA
Keyword(s):  
Wavelet Analysis ◽  
Axial Compressor ◽  
Rotating Stall ◽  
Compressor Rotor

Prediction of Rotating Stall Inception in an Axial Compressor Rotor using CFD

2004 ◽  
Vol 2004.3 (0) ◽  
pp. 339-340
Author(s):  
Masato FURUKAWA ◽  
Isao TOMITA ◽  
Takurou KAMEDA ◽  
Kazutoyo YAMADA ◽  
Masahiro INOUE
Keyword(s):  
Axial Compressor ◽  
Rotating Stall ◽  
Stall Inception ◽  
Compressor Rotor

scholarly journals Numerical Simulation of Rotating Stall in Axial Compressor Blade Rows and Stages

1986 ◽  
Author(s):  
H. G. Neuhoff ◽  
K. G. Grahl
Keyword(s):  
Axial Compressor ◽  
Rotating Stall ◽  
Compressor Blade ◽  
Time Step ◽  
Time Constants ◽  
Compressor Rotor ◽  
Cascade Flow ◽  
Flow Through ◽  
Transonic Fan ◽  
Highly Loaded

Rotating stall is simulated by a time step integration procedure of the Euler equations. The prescribed compressors consist of finite inlet and outlet ducts, blade rows of finite chord lengths and a throttle without impedance. Due to this compressor model the net mass flow through the compressor remains constant during the transient to fully developed rotating stall. Results are presented for a highly loaded rotor and a transonic fan stage. Contrary to former nonlinear approaches, the presented theory indicates that the fully developed rotating stall in a single compressor rotor is not affected by the number of lobes of an initial circumferential disturbance. For a highly loaded stage the dependence of the stall parameters on the time constants of the cascade flow is demonstrated.

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