Detecting Rotating Stall Precursors in Axial Compressors via Perturbations Part 1: Theory

2014 ◽  
Vol 30 (5) ◽  
pp. 1295-1306 ◽  
Author(s):  
Wanjing Dong ◽  
Yong Wang
Keyword(s):  
Rotating Stall ◽  
Axial Compressors

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

2020 ◽  
Vol 5 (3) ◽  
pp. 16 ◽  
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.

Detection of Precursor Waves Announcing Stall in Two 3-Stage Axial Compressors

1998 ◽  
Author(s):  
F. Grauer ◽  
W. Volgmann ◽  
H. Stoff ◽  
T. Breuer
Keyword(s):  
Pressure Fluctuations ◽  
Safety Margin ◽  
Stability Limit ◽  
Rotating Stall ◽  
Time Dependent ◽  
Axial Compressors ◽  
Performance Map ◽  
Fourier Transform Methods ◽  
The Stability ◽  
Stall Control

Rotating stall and surge limit the operating range of a compressor towards low throughflow and high pressure in the performance map. Usually a safety margin must be observed to prevent the compressor from entering unintentionally aerodynamic instabilities. As the range of highest performance and efficiency lies in the vicinity of the stability limit, efforts concentrate on recognizing imminent onset of unstable operation prior to its occurrence. The present investigation centers on means of detecting information about onsetting instability from signals of pressure fluctuations in two transonic medium-pressure axial compressors of 3 stages. Fourier-transform-methods as well as artificial neural networks are applied for the data reduction of the time-dependent pressure signals. The methods of investigation presented here detected stall precursors announcing the onset of instability. Some of them seem appropriate to be used in connection with active stall control.

Experimental Study of Rotating Stalls in a Four-Stage Axial Compressor

2002 ◽  
Author(s):  
Y. Levy ◽  
J. Pismenny ◽  
A. Reissner ◽  
W. Riess
Keyword(s):  
Cross Section ◽  
Axial Compressor ◽  
Pressure Oscillation ◽  
Transverse Cross Section ◽  
Rotating Stall ◽  
Pressure Variation ◽  
Time Diagram ◽  
Rotor Speed ◽  
Axial Compressors

The relationships between the frequencies of pressure oscillation ωOSC and the rotor speed (frequencies of rotor rotation) ωRR, as well as between the phases of pressure oscillation and geometrical angles of the sensor locations on the compressor casing (in the transverse cross-section) were determined experimentally. In addition, the phase–location relation permitted determination of the number of stall cells under established rotating stall. Literature on rotating stall in axial compressors typically refers to rotating stall with frequencies less than the rotor speed. This paper is concerned with two types of rotating stall, observed during experiments in a four-stage axial compressor, operating at the same rotor speed, n/nd = 0.95, where n is the rotor speed and nd the rotor data-sheet speed. The rotating stall frequencies were both, smaller and larger than the rotor speed. The relationships between ωOSC and ωRR were determined by four methods: directly from the time diagram of the pressure oscillation, from the diagrams of pressure variation in space and time, from the autocorrelation characteristics, and from the frequency characteristics of the pressure signals. All methods indicated values of ωOSC/ωRR in the form of integer ratios, 3:7 and 11:2. The phases of pressure oscillation in the transverse cross-section are equal to the sensor angles in compressor stator (in the case ωOSC/ωRR = 3:7) or are three times larger (in the case ωOSC/ωRR = 11:2), in accordance with the classical theory of single-cell and three-cell configurations of rotating stall, respectively.

Tailored Structural Design and Aeromechanical Control of Axial Compressor Stall: Part II — Evaluation of Approaches

2003 ◽  
Author(s):  
L. G. Fre´chette ◽  
O. G. McGee ◽  
M. B. Graf
Keyword(s):  
Structural Parameters ◽  
Axial Compressor ◽  
Coupled System ◽  
Rotating Stall ◽  
Rotor Blades ◽  
Tip Clearance ◽  
Theoretical Evaluation ◽  
Axial Compressors ◽  
Spatial Modes ◽  
Control Authority

A theoretical evaluation was conducted delineating how aeromechanical feedback control can be utilized to stabilize the inception of rotating stall in axial compressors. Ten aeromechanical control methodologies were quantitatively examined based on the analytical formulations presented in the first part of this paper (McGee et al, 2003a). The maximum operating range for each scheme is determined for optimized structural parameters, and the various schemes are compared. The present study shows that the most promising aeromechanical designs and controls for a class of low-speed axial compressors were the use of dynamic fluid injection. Aeromechanically incorporating variable duct geometries and dynamically re-staggered IGV and rotor blades were predicted to yield less controllability. The aeromechanical interaction of a flexible casing wall was predicted to be destabilizing, and thus should be avoided by designing sufficiently rigid structures to prevent casing ovalization or other structurally-induced variations in tip clearance. Control authority, a metric developed in the first part of this paper, provided a useful interpretation of the aeromechanical damping of the coupled system. The model predictions also show that higher spatial modes can become limiting with aeromechanical feedback, both in control of rotating stall as well as in considering the effects of lighter, less rigid structural aeroengine designs on compressor stability.

The Measurement and Interpretation of Flow within Rotating Stall Cells in Axial Compressors

1978 ◽  
Vol 20 (2) ◽  
pp. 101-114 ◽  
Author(s):  
I. J. Day ◽  
N.A. Cumpsty
Keyword(s):  
Flow Direction ◽  
Axial Flow ◽  
Tangential Direction ◽  
Rotating Stall ◽  
Design Flow ◽  
Flow Measurements ◽  
Axial Compressors ◽  
Multi Stage ◽  
Wide Range ◽  
Flow Compressor

Detailed flow measurements obtained by a new measuring technique are presented for the flow in a stalled axial-flow compressor. Results were obtained from a wide range of compressor builds, including multi-stage and single-stage configurations of various design flow rates and degrees of reaction. Instantaneous recordings of absolute velocity, flow direction and total and static pressures have been included for both full-span and part-span stall. With the aid of these results, it has been shown that the conventional model of the flow in a stall cell is erroneous. An alternative model is proposed, based on the observation that the fluid must cross from one side of the cell to the other in order to preserve continuity in the tangential direction. An investigation of the experimental results also reveals the finer details of the flow in the cell and shows how these details are related to the design flow rate of the compressor. The influence of these cell details on the power absorbed by a stalled compressor are investigated, and consideration is given to the complex pressure patterns encountered in the compressor.

Theoretical Study of Flow Instabilities and Inlet Distortions in Axial Compressors

1982 ◽  
Vol 104 (3) ◽  
pp. 715-721 ◽  
Author(s):  
P. Ferrand ◽  
J. Chauvin
Keyword(s):  
Theoretical Study ◽  
Rotating Stall ◽  
Time Dependent ◽  
Flow Instabilities ◽  
Axial Compressors ◽  
Independent Variables ◽  
Servo Mechanism ◽  
Dependent Variables ◽  
Multistage Compressors ◽  
Method Of Evaluation

This paper describes a method of evaluation of the single and multistage compressors response to steady and unsteady inlet distortions. It allows also the evaluation of the appearance of unstable regimes and their characterization (rotating stall and surge). It is based on a linearized approach using mean line calculations. The compressor is considered as a series of vaned and vaneless spaces, and the corresponding equations are solved by use of Fourier series for time independent variables and by Laplace’s transform for time-dependent variables. An analogy between the compressor’s response and a servo-mechanism is developed, using Nyquist’s diagram. Results are compared with experimental data which prove the validity of the approach. A parametric study indicates which parameters can be modified to improve the flow stability.

Surge and rotating stall in axial compressors

1989 ◽  
Author(s):  
H. ISHII ◽  
Y. KASHIWABARA
Keyword(s):  
Rotating Stall ◽  
Axial Compressors
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