Stall Warning of Axial Compressor Using Spatial FFT and Combined Analysis of Multiple Statistical Parameters

In this study, characteristics of stall inception in a single-stage transonic axial compressor with circumferential grooves casing treatment were investigated experimentally. Additionally, the characteristic of increasing irregularity in the pressure inside circumferential grooves as the compressor approaches the stall limit was applied to the stall warning method. Spike-type rotating stall was observed in the single-stage transonic axial compressor with smooth casing. When circumferential grooves were applied, the stall inception was suppressed and the operating point of the compressor moved to lower flow rate than the stall limit. A spike-like disturbance was developed into a rotating stall cell and then the Helmholtz perturbation was overlapped on it at N = 80%. At N = 70 %, the Helmholtz perturbation was observed first and the amplitude of the wave gradually increased as mass flow rate decreased. At N = 60%, spike type stall inceptions were observed intermittently and then developed into continuous rotating stall at lower mass flow rate. Pressure measured at the bottom of circumferential grooves showed that the level of irregularity of pressure increased as flow rate decreased. Based on the characteristic of increasing irregularity of the pressure signals inside the circumferential grooves as stall approaches, an autocorrelation technique was applied to the stall warning. This technique could be used to provide warning against stall and estimate real-time stall margins in compressors with casing treatments.

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Comparison and Sensibility Analysis of Warning Parameters for Rotating Stall Detection in an Axial Compressor

International Journal of Turbomachinery Propulsion and Power ◽

10.3390/ijtpp5030016 ◽

2020 ◽

Vol 5 (3) ◽

pp. 16 ◽

Cited By ~ 2

Author(s):

Gabriel Margalida ◽

Pierric Joseph ◽

Olivier Roussette ◽

Antoine Dazin

Keyword(s):

Research Work ◽

Axial Compressor ◽

Rotating Stall ◽

Stall Inception ◽

Axial Compressors ◽

Sensibility Analysis ◽

Stall Warning ◽

Two Parameters ◽

Unsteady Pressure Measurements

The present paper aims at evaluating the surveillance parameters used for early stall warning in axial compressors, and is based on unsteady pressure measurements at the casing of a single stage axial compressor. Two parameters—Correlation and Root Mean Square (RMS)—are first compared and their relative performances discussed. The influence of sensor locations (in both radial and axial directions) is then considered, and the role of the compressor’s geometrical irregularities in the behavior of the indicators is clearly highlighted. The influence of the throttling process is also carefully analyzed. This aspect of the experiment’s process appears to have a non-negligible impact on the stall warning parameters, despite being poorly documented in the literature. This last part of this research work allow us to get a different vision of the alert parameters compared to what is classically done in the literature, as the level of irregularity that is reflected by the magnitude of the parameters appears to be an image of a given flow rate value, and not a clear indicator of the stall inception.

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Experimental Investigation of a Stall Prediction System Using a Transonic Multistage Compressor

Volume 6: Turbo Expo 2007, Parts A and B ◽

10.1115/gt2007-28199 ◽

2007 ◽

Cited By ~ 1

Author(s):

Tomofumi Nakakita ◽

Masahiro Kurosaki ◽

Yukio Kamiyoshihara

Keyword(s):

Axial Compressor ◽

Prediction System ◽

Test Results ◽

Stall Margin ◽

Pressure Transducers ◽

Stator Vane ◽

Multistage Compressor ◽

Stall Warning ◽

Stall Control ◽

Multistage Axial Compressor

This paper describes the test results of a stall prediction system using a transonic multistage axial compressor. The test results show that there is a clear relationship between the stall margin and the stall-warning index measured at the first stage. The stall warning index is derived from auto correlation of casing wall pressure signals above the rotor tip. In the tests, the compressor installed with pressure transducers on the casing wall near the leading edges of the first three rotors was forced to stall while operating at a constant speed by closing the discharge valve. The test results where the stator vane settings of the first three stages were changed show that load distribution among stages does not have significant effects on the stall margin vs. stall-warning index relationship. Using some smoothing technique, undesired time variation of the stall-warning index can be reduced to the level necessary for practical active stall control with allowable response time delay.

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Algorithm of axial compressor stall warning based on BP neural network and fuzzy logic

MATEC Web of Conferences ◽

10.1051/matecconf/202235503007 ◽

2022 ◽

Vol 355 ◽

pp. 03007

Author(s):

Xiaohong Qiu ◽

Jiali Chen

Keyword(s):

Neural Network ◽

Fuzzy Logic ◽

Early Warning ◽

Bp Neural Network ◽

Axial Compressor ◽

Time Sequence ◽

A Algorithm ◽

Stall Warning ◽

All Speeds ◽

Logic Reasoning

Stall warning of axial compressor is very challenging and the existing warning margin is not enough. A algorithm based on BP neural network fusion fuzzy logic is proposed. Firstly, BP neural network is used for training recognition, next the identification results are fused with fuzzy logic reasoning to form the result judgment of time sequence, finally the stall early warning of axial compressor is realized. The simulation results of the experimental data show that the stall data at all speeds are at least 0.1s in advance of the early warning. Compared with other methods, this method has a better surge early warning margin performance and engineering practicability.

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Application of wavelet analysis on early stall warning in the axial compressor

10.29008/etc2019-285 ◽

2019 ◽

Author(s):

Yang Liu ◽

Jichao Li ◽

Juan Du ◽

Hongwu Zhang

Keyword(s):

Wavelet Analysis ◽

Axial Compressor ◽

Stall Warning

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A Novel Stall Warning Indicator: Part II — Underlying Flow Mechanism

Volume 1: Aircraft Engine; Fans and Blowers; Marine; Honors and Awards ◽

10.1115/gt2019-90243 ◽

2019 ◽

Author(s):

Mario Eck ◽

Roland Rückert ◽

Marc Lehmann ◽

Dieter Peitsch

Keyword(s):

Axial Compressor ◽

Propagation Speed ◽

Flow Coefficient ◽

Spectral Signature ◽

The Novel ◽

Time Resolved ◽

Pressure Transducers ◽

Flow Disturbances ◽

Stall Warning ◽

Rotating Instability

Abstract The aim of the present paper is to improve the physical understanding of flow irregularities in the blade passing signal of turbomachinery rotors, since the novel stall warning method presented in part I is based upon those irregularities. For this purpose, a complementary instrumentation was used in a single stage axial compressor. A set of pressure transducers evenly distributed along the circumference surface mounted in the casing near the rotor tip leading edges is measuring the time-resolved wall pressures simultaneously to an array of transducers recording the chord-wise static pressures. The latter allows for plotting quasi-instantaneous 2D-pressure contours. Any occurring flow disturbances causing the before mentioned irregularity can later be classified using validated frequency analysis methods being applied to the data from the circumferential sensors. While leaving the flow coefficient constant, a continuously changing number of prestall flow disturbances appears to be causing the very spectral signature which is known from investigations on Rotating Instability. Any arising number of disturbances is matching a specific mode order to be found within the spectral signature. While the flow coefficient is reduced the propagation speed of prestall disturbances increases linearly as the speed seems to be independent from the clearance size. Data taken beyond the stalling limit demonstrate a complex superposition of stall cells and flow disturbances which the title “prestall disturbance” therefore doesn’t fit to precisely any more. Different convection speeds allow the phenomena to be clearly distinguished from each other.

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A Novel Stall Warning Indicator: Part I — Applications and Limitations

Volume 1: Aircraft Engine; Fans and Blowers; Marine; Honors and Awards ◽

10.1115/gt2019-90242 ◽

2019 ◽

Author(s):

Roland Rückert ◽

Mario Eck ◽

Dieter Peitsch ◽

Marc Lehmann

Keyword(s):

High Speed ◽

Axial Compressor ◽

Leading Edge ◽

Experimental Tests ◽

Axial Direction ◽

Time Resolved ◽

Compressor Rotor ◽

Flight Operations ◽

Stall Warning ◽

The Impact

Abstract The present work is the first of two papers investigating the operation principle of stall warning quantities. It discusses the use and implementation of novel stall warning techniques based on experimental tests. Each of the addressed techniques is based upon integral statistical analysis of time-resolved wall pressures in close proximity to the leading edge of a compressor rotor. The experiments were conducted on a low speed axial compressor test rig at the Chair of Aeroengines at the Technische Universität Berlin. The compressor suffers from a specific type of pre-stall instability. The signature within the frequency spectrum of this semi-stable operating point is in itself unique and was observed by many within the scientific community on numerous occasions and various axial compressor types, both low and high speed. Strong evidence has been elaborated which indicate that each of those so called stall warning indicator’s functionality is based upon the existence of this prestall phenomena. The first of two indicators is time-dependent as it evaluates the as-is state against surrounding operating points during transient manoeuvres. Furthermore, the impact of varying geometrical boundary conditions, which are known to regularly arise in flight operations, were taken into account. The functionality of the indicator is assured if the instrumentation is adjusted accordingly. The second indicator is mainly a location-dependent quantity as it evaluates the pressure signature along the axial direction within the rotor passage at various aerodynamic loadings. The latter also gave rise to some fundamental and preliminary understanding of the physics behind so called prestall disturbances.

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