scholarly journals Analysis Methods for Aerodynamic Instability Detection on a Multistage Axial Compressor

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Baofeng Tu ◽  
Xinyu Zhang ◽  
Jun Hu ◽  
Ming Zhong ◽  
Bing Xiong
Keyword(s):  
High Speed ◽  
Axial Compressor ◽  
Mean Amplitude ◽  
Rotating Stall ◽  
Variance Analysis ◽  
Analysis Method ◽  
Amplitude Analysis ◽  
Analysis Methods ◽  
Aerodynamic Instability ◽  
Multistage Axial Compressor

In order to detect the aerodynamic instability of a multistage axial compressor more accurately and earlier, the harmonic Fourier mean amplitude analysis method and heterotopic variance analysis method are developed. The dynamic instability prediction performance of the two methods is studied on a low-speed and a high-speed two-stage axial compressor. The harmonic Fourier mean amplitude analysis method is suitable for predicting the aerodynamic instability of a multistage axial compressor in the form of a rotating stall. Compared with the traditional harmonic Fourier analysis methods, the harmonic Fourier mean amplitude analysis method can capture the detail of the pressure signal more accurately and it can effectively prevent instability misjudgment. The heterotopic variance analysis method is developed based on the conventional variance analysis method, and it can be used to distinguish whether the compressor is in the rotating stall or the surge state. The heterotopic variance analysis method can predict the aerodynamic instability ahead of the harmonic Fourier mean amplitude analysis method, and fewer circumferential measuring points were employed. The layout of the measuring points also influences the detection of the aerodynamic instability of the compressor. The aerodynamic instability of the high-speed axial compressor can be predicted earlier by employing measuring points at the compressor outlet.

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.

Characteristics of Stable Rotating Stall Cells in an Axial Compressor

2017 ◽  
Author(s):  
Adam R. Hickman ◽  
Scott C. Morris
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Pressure Ratio ◽  
Pressure Sensors ◽  
Axial Compressor ◽  
Field Measurements ◽  
Rotating Stall ◽  
Flow Coefficient ◽  
Stable Operation ◽  
Double Phase

Flow field measurements of a high-speed axial compressor are presented during pre-stall and post-stall conditions. The paper provides an analysis of measurements from a circumferential array of unsteady shroud static pressure sensors during stall cell development. At low-speed, the stall cell approached a stable size in approximately two rotor revolutions. At higher speeds, the stall cell developed within a short amount of time after stall inception, but then fluctuated in circumferential extent as the compressor transiently approached a stable post-stall operating point. The size of the stall cell was found to be related to the annulus average flow coefficient. A discussion of Phase-Locked Average (PLA) statistics on flow field measurements during stable operation is also included. In conditions where rotating stall is present, flow field measurements can be Double Phase-Locked Averaged (DPLA) using a once-per-revolution (1/Rev) pulse and the period of the stall cell. The DPLA method provides greater detail and understanding into the structure of the stall cell. DPLA data indicated that a stalled compressor annulus can be considered to contained three main regions: over-pressurized passages, stalled passages, and recovering passages. Within the over-pressured region, rotor passages exhibited increased blade loading and pressure ratio compared to pre-stall values.

Active Stabilization of Rotating Stall in a Three-Stage Axial Compressor

1993 ◽  
Author(s):  
Joel M. Haynes ◽  
Gavin J. Hendricks ◽  
Alan H. Epstein
Keyword(s):  
High Speed ◽  
Travelling Waves ◽  
Axial Compressor ◽  
Open Loop ◽  
Rotating Stall ◽  
Forced Response ◽  
Flow Coefficient ◽  
Design Parameters ◽  
Time Lags ◽  
Active Stabilization

A three-stage, low speed axial research compressor has been actively stabilized by damping low amplitude circumferentially travelling waves which can grow into rotating stall. Using a circumferential array of hot wire sensors, and an array of high speed individually positioned control vanes as the actuator, the first and second spatial harmonics of the compressor were stabilized down to a characteristic slope of 0.9, yielding an 8% increase in operating flow range. Stabilization of the third spatial harmonic did not alter the stalling flow coefficient. The actuators were also used open loop to determine the forced response behavior of the compressor. A system identification procedure applied to the forced response data then yielded the compressor transfer function. The Moore-Greitzer, 2-D, stability model was modified as suggested by the measurements to include the effect of blade row time lags on the compressor dynamics. This modified Moore-Greitzer model was then used to predict both the open and closed loop dynamic response of the compressor. The model predictions agreed closely with the experimental results. In particular, the model predicted both the mass flow at stall without control and the design parameters needed by, and the range extension realized from, active control.

Considerations for Using 3D Pneumatic Probes in High Speed Axial Compressors

2002 ◽  
Author(s):  
Simon Coldrick ◽  
Paul Ivey ◽  
Roger Wells
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Pressure Probe ◽  
Probe Type ◽  
Calibration Data ◽  
Axial Compressors ◽  
Close Proximity ◽  
Multistage Axial Compressor ◽  
Preparatory Work

This paper describes preparatory work towards three dimensional flowfield measurements downstream of the rotor in an industrial, multistage, axial compressor, using a pneumatic pressure probe. The probe is of the steady state four hole cobra probe type. The design manufacture and calibration of the probe is described. CFD calculations have been undertaken in order to assess the feasability of using such a probe in the high speed compressor environment where space is limited. This includes effects of mounting the probe in close proximity to the downstream stator blades and whether it is necessary to adjust the calibration data to compensate for these effects.

J011021 Large-Scale Numerical Analysis of Rotating Stall Inception in a Multistage Axial Compressor

2013 ◽  
Vol 2013 (0) ◽  
pp. _J011021-1-_J011021-5
Author(s):  
Masato FURUKAWA ◽  
Kazutoyo YAMADA ◽  
Yoshihiro HAYASHI ◽  
Akinori MATSUOKA ◽  
Kentaro NAKAYAMA
Keyword(s):  
Numerical Analysis ◽  
Large Scale ◽  
Axial Compressor ◽  
Rotating Stall ◽  
Stall Inception ◽  
Multistage Axial Compressor

Validation of a 1D Transient Simulation Model of a Multistage Axial Compressor

2015 ◽  
Author(s):  
Reema Kundu ◽  
J. V. R. Prasad ◽  
Yedidia Neumeier
Keyword(s):  
Axial Compressor ◽  
Rotating Stall ◽  
Second Order ◽  
Working Fluid ◽  
Uniform Grid ◽  
Computational Domain ◽  
Source Terms ◽  
One Dimensional ◽  
The Impact ◽  
Multistage Axial Compressor

An unsteady one-dimensional dynamic model has been developed at Georgia Tech to investigate the impact of stage characteristics as well as load distribution on the compression and expansion waves that develop prior to a surge event in a multistage axial compressor. In the developed model, each of the blade rows is replaced by a duct of varying cross-sectional area with force and work source terms. The source terms model the force and energy imparted by a blade row to the working fluid. The modeling assumes the flow to be inviscid, unsteady, compressible and axisymmetric. While rotating stall cannot be explicitly modeled in a 1D mean-line method, the effect of rotating stall can be captured by a judicious choice of source terms that reflects the loss of pumping capability of a stage. Conservation of mass, momentum and energy are applied to an elemental control volume resulting in one-dimensional quasi-linear Euler system of equations. A non-uniform grid and the second-order central difference Kurganov-Tadmor (KT) scheme are used to discretize the one-dimensional computational domain. The resulting ODEs are solved with an explicit second order Runge-Kutta solver. A throttle schedule is used to introduce perturbations at a selected operating condition in order to study flow oscillations that can lead to a stall event. The current study is aimed at validation of the developed flow solver using an industrial compressor database. Further, the current study is aimed at understanding the interaction between the stages with regards to pressure oscillations leading to stall.

Examination of Rotating Stall Inception in a Small High Speed Axial Compressor

2009 ◽  
Author(s):  
L. G. N. Bennett ◽  
W. D. E. Allan
Keyword(s):  
High Speed ◽  
Gasoline Engine ◽  
Axial Compressor ◽  
Rotating Stall ◽  
Operating Conditions ◽  
Pressure Measurements ◽  
Operating Life ◽  
Fourier Decomposition ◽  
Stall Inception ◽  
Prediction And Prevention

Rotating stall is an internal aerodynamic disturbance that limits the performance and operating life of a compressor. It has been studied with the aim of developing techniques for its prediction and prevention. To further the understanding of rotating stall inception, a test rig was constructed with the axial stages of a Rolls Royce Model 250-C20B small, high speed axial compressor as the test article. A gasoline engine was used to power the compressor and airflow was throttled through a pneumatically controlled valve. Simultaneous static pressure measurements were taken with seven high speed transducers arranged in two configurations: distributed both axially and circumferentially around the compressor casing. The compressor characteristic was mapped and detailed pressure measurements were taken between normal and surge operating conditions. Previous studies of high speed multi-stage compressors have shown both modal and spike type stall inception at different compressor stages. Other examinations of the Model 250 compressor have shown stall inception occurring at the first stage of the compressor. Similar results were observed in this study and an analysis was conducted using a variety of signal processing techniques including pressure trace inspection and discrete spatial Fourier decomposition.

Calibration of a V-Cone for Low Mass Flows for Small Core Compressor Research

2020 ◽  
Author(s):  
Julia E. Stephens ◽  
Sameer Kulkarni
Keyword(s):  
Mass Flow ◽  
High Speed ◽  
Pressure Ratio ◽  
Axial Compressor ◽  
Flow Rates ◽  
Turbofan Engines ◽  
Mass Flow Rates ◽  
Low Mass ◽  
Mass Flows ◽  
Multistage Axial Compressor

Abstract Advancements in core compressor technologies are necessary for next generation, high Overall Pressure Ratio (OPR) turbofan engines. High pressure compressors (HPCs) for future engines are being designed with exit corrected mass flow rates less than 2.25 kg/s (5 lbm/s). In order to accurately measure the performance of these advanced designs, high accuracy measurements are needed in test facilities. The W7 High Speed Multistage Axial Compressor Facility at NASA Glenn Research Center has been used to acquire data for advanced compressor designs. This facility utilizes an advanced differential pressure flow meter called a V-Cone. The facility has historically tested components with physical mass flow rates in the range of 27 to 45 kg/s (60 to 100 lbm/s). As such, when the V-Cone was calibrated prior to installation, the calibrations focused on higher mass flow rates, and uncertainties in that regime range from 0.5% to 0.85%. However, for low mass flow rates under 9 kg/s (20 lbm/s), expected in tests of advanced high OPR HPCs rear stages, the uncertainties of the V-Cone exceed 2.5%. To address this, using a method similar to that utilized by the National Institute of Standards and Technology, an array of Critical Flow Venturi Nozzles (CFVs) was installed in the W7 test section and used to calibrate the V-Cone in 0.5 kg/s (1 lbm/s) increments up to 10.5 kg/s (23 lbm/s). This effort details the measurements and uncertainties associated with this calibration which resulted in a final uncertainty of the V-Cone measurements under 1%.

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