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.

Stall Warning Using the Rotor Tip Pressure in a Transonic Axial Compressor With Circumferential Grooves

2018 ◽  
Author(s):  
Byeung Jun Lim ◽  
Tae Choon Park ◽  
Young Seok Kang
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Axial Compressor ◽  
Rotating Stall ◽  
Single Stage ◽  
Stall Inception ◽  
Casing Treatment ◽  
Stall Warning ◽  
Transonic Axial Compressor

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.

Aeromechanical Control of High-Speed Axial Compressor Stall and Engine Performance— Part I: Control-Theoretic Models

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
O. G. McGee ◽  
K. L. Coleman
Keyword(s):  
High Speed ◽  
Axial Compressor ◽  
Engine Performance ◽  
Maximum Flow ◽  
Rotating Stall ◽  
Design Flow ◽  
Systematic Evaluation ◽  
Stable Operation ◽  
Stall Inception ◽  
Axial Compressors

General methodologies are proposed in this two-part paper that further phenomenological understanding of compressible stall inception and aeromechanical control of high-speed axial compressors and engine performance. Developed in Part I are strategies for passive stabilization of compressible rotating stall, using tailored structural design and aeromechanical feedback control, implemented in certain classes of high-speed axial compressors used in research laboratories and by industry. Fundamentals of the stability of various dynamically-compensated, high-speed compressors was set down from linearized, compressible structural-hydrodynamic equations of modal stall inception extended further in this study from previous work. A dimensionless framework for performance-based design of aeromechanically-controlled compression system stall mitigation and engine performance is established, linking specified design flow and work-transfer (pressure) operability to model stages or local blade components, velocity triangle environment, optimum efficiency, extended stall margin and operability loci, and aeromechanical detailed design. A systematic evaluation was made in Part II (Coleman and McGee, 2013, “Aeromechanical Control of High-Speed Axial Compressor Stall and Engine Performance—Part II: Assessments of Methodology,” ASME J. Fluids Eng. (to be published)) on the performance of ten aeromechanical feedback controller schemes to increase the predicted range of stable operation of two laboratory compressor characteristics assumed, using static pressure sensing and local structural actuation to rudimentary postpone high-speed modal stall inception. The maximum flow operating range for each of the ten dynamically-compensated, high-speed compression systems was determined using optimized or “tailored” structural controllers, and the results described in Part II of the companion paper are compared to maximum operating ranges achieved in corresponding low-speed compression systems.

scholarly journals Detailed Pressure Measurements During the Transition to Rotating Stall in an Axial Compressor: Influence of the Throttling Process

2018 ◽  
Author(s):  
Gabriel Margalida ◽  
Antoine Dazin ◽  
Pierric Joseph ◽  
Olivier Roussette
Keyword(s):  
Axial Compressor ◽  
Warning Signal ◽  
Rotating Stall ◽  
Pressure Measurements ◽  
Pressure Signal ◽  
Instability Development ◽  
Stable Operating ◽  
Instantaneous Pressure ◽  
Reference Pressure ◽  
Unsteady Pressure Measurements

This paper presents experimental unsteady pressure measurements gathered on a single stage axial compressor during pre-stall and transition to stall operations. The aim of this study is to analyze the transition from a stable operating point to the fully developed rotating stall regime, and more specifically, the effect of the throttling process on the development of the instabilities. To do so, experiments have been repeated leading the compressor to stall operations with various throttling speed. On one hand, this paper analyses the effect of the throttling speed on the dynamic of the instability development from the first detection of spike type precursors to completely developed rotating stall. On the other hand, a stall warning signal based on the correlation of the instantaneous pressure signal with a reference pressure signal is built. The influence of the location of the pressure transducer used for the warning signal is first analyzed. Then an analysis of the effect of the throttling process on the time between the warning signal and the effective stall development is proposed.

Effects of inlet radial distortion on the type of stall precursor in low-speed axial compressor

2016 ◽  
Vol 232 (1) ◽  
pp. 55-67 ◽  
Author(s):  
Ali Arshad ◽  
Qiushi Li ◽  
Simin Li ◽  
Tianyu Pan
Keyword(s):  
Pressure Fluctuations ◽  
Axial Compressor ◽  
Rotating Stall ◽  
Experimental Investigations ◽  
Inlet Flow ◽  
Blade Loading ◽  
Stall Inception ◽  
Low Speed ◽  
Modal Type ◽  
Stall Precursor

Experimental investigations of the effect of inlet blade loading on the rotating stall inception process are carried out on a single-stage low-speed axial compressor. Temporal pressure signals from the six high response pressure transducers are used for the analysis. Pressure variations at the hub are especially recorded during the stall inception process. Inlet blade loading is altered by installing metallic meshed distortion screens at the rotor upstream. Three sets of experiments are performed for the comparison of results, i.e. uniform inlet flow, tip, and hub distortions, respectively. Regardless of the type of distortion introduced to the inflow, the compressor undergoes a performance drop, which is more severe in the hub distortion case. Under the uniform inlet flow condition, stall inception is caused by the modal type disturbance while the stall precursor switched to spike type due to the highly loaded blade tip. In the presence of high blade loading at the hub, spike disappeared and the compressor once again witnessed a modal type disturbance. Hub pressure fluctuations are observed throughout the process when the stall is caused by a modal wave while no disturbance is noticed at the hub in spike type stall inception. It is believed that the hub flow separation contributes to the modal type of stall inception phenomenon. Results are also supported by the recently developed signal processing techniques for the stall inception study.

Numerical Investigations on Partial Surge Initiated Inception and Stall Evolution in a Transonic Compressor

2017 ◽  
Author(s):  
Jiaguo Hu ◽  
Tianyu Pan ◽  
Wenqian Wu ◽  
Qiushi Li ◽  
Yifang Gong
Keyword(s):  
High Performance ◽  
Axial Compressor ◽  
Pressure Rise ◽  
Rotating Stall ◽  
Rapid Decline ◽  
Second Phase ◽  
Stall Inception ◽  
Transonic Compressor ◽  
Transient Simulations ◽  
Two Factors

The instability has been the largest barrier of the high performance axial compressor in the past decades. Stall inception, which determines the route and the characteristics of instability evolution, has been extensively focused on. A new stall inception, “partial surge”, is discovered in the recent experiments. In this paper full-annulus transient simulations are performed to study the origin of partial surge initiated inception and explain the aerodynamic mechanism. The simulations show that the stall inception firstly occurs at the stator hub region, and then transfers to the rotor tip region. The compressor finally stalled by the tip region rotating stall. The stall evolution is in accord with the experiments. The stall evolution can be divided into three phases. In the first phase, the stator corner separation gradually merged with the adjacent passages, producing an annulus stall cell at the stator hub region. In the second phase, the total pressure rise of hub region emerges rapid decline due to the fast expansion of the annulus stall cell, but the tip region maintains its pressure rise. In the third phase, a new rotating stall cell appears at the rotor tip region, leading to the onset of fast drop of the tip region pressure rise. The stall cells transfer from hub region to the tip region is caused by two factors, the blockage of the hub region which transfers more load to the tip region, and the separation fluid fluctuations in stator domain which increase the circumferential non-uniformity in the rotor domain. High load and non-uniformity at the rotor tip region induce the final rotating stall.

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.

Dynamic Characterization and Identification of Flow in a Blade Passage in Near-Stall Conditions of Axial Compressor Systems

2019 ◽  
Author(s):  
Eighdi Aung ◽  
Marco P. Schoen ◽  
Jichao Li
Keyword(s):  
Correlation Coefficient ◽  
Active Flow Control ◽  
Axial Compressor ◽  
Leading Edge ◽  
Rotating Stall ◽  
Operating Conditions ◽  
Sensor Data ◽  
Detection Methods ◽  
Operating Point ◽  
Stall Inception

Abstract Axial compressor systems are susceptible to unstable conditions near their optimal operating point. In particular, rotating stall and surge are conditions that need to be avoided during the operation of an axial compressor. In extreme cases these conditions may cause damage to the compressor. The onset of either condition is rather rapid, and usually does not allow for remedial control action based on the limited time available. Hence, research efforts have been focusing on the development of new detection methods that allow for more time to take corrective measures. This paper explores and compares various existing and proposed methods to identify and detect those precursors. The methods detailed in this work are tested at different operating conditions and locations. The methods investigated include the sequentially computed correlation coefficient of pressure sensor data, correlation coefficient, the Generalized Extreme Studentized Deviate Test (ESD) for outlier detection, spectral entropy, and Autoregressive (AR) models. The primary goal of evaluating these methods is based on their suitability for employment as pre-processors for dynamic system identification. By using the dynamics of the identified model rather than a static precursor, it is stipulated that the onset of stall and surge can be managed with a control concept. For this work, the extracted models are investigated for suitability to serve as precursors, and the potential as predictive models. This work may serve for future work to achieve active flow control by direct air injection at the leading edge of the blades. For this work, a one-stage compressor system with a blade geometry that allows for spike inception is utilized. Spike stall inception is a precursor to fully developed rotating stall. The subsonic compressor has 60 blades, and its operating point is controlled by a throttle and constant speed control of the rotor. The pressure data is collected with 10 Kulite™ sensors which are placed along the blade cord length on the outer casing of the compressor. The results of the tabulated performance of the various methods and resulting models indicate that an ARESD combination yields the earliest indication for spike stall inception.

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.

About the Numerical Simulation of Rotating Stall Mechanisms in Axial Compressors

2006 ◽  
Author(s):  
N. Gourdain ◽  
S. Burguburu ◽  
G. J. Michon ◽  
N. Ouayahya ◽  
F. Leboeuf ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Pressure Rise ◽  
Rotating Stall ◽  
Tip Clearance ◽  
Stall Inception ◽  
Axial Compressors ◽  
Time Frequency ◽  
Flow Phenomena ◽  
Temporal Modes ◽  
Inception Point

This paper deals with the first instability which occurs in compressors, close to the maximum of pressure rise, called rotating stall. A numerical simulation of these flow phenomena is performed and a comparison with experimental data is made. The configuration used for the simulation is an axial single-stage and low speed compressor (compressor CME2, LEMFI). The whole stage is modeled with a full 3D approach and tip clearance is taken into account. The numerical simulation shows that at least two different mechanisms are involved in the stall inception. The first one leads to a rotating stall with 10 cells and the second one leads to a configuration with only 3 cells. Unsteady signals from the computation are analyzed thanks to a time-frequency spectral analysis. An original model is proposed, in order to predict the spatial and the temporal modes which are the results of the interaction between stall cells and the compressor stage. A comparison with measurements shows that the computed stall inception point corresponds to the experimental limit of stability. The performance of the compressor during rotating stall is also well predicted by the simulation.

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