Surge and Rotating Stall in Axial Flow Compressors—Part II: Experimental Results and Comparison With Theory

1976 ◽  
Vol 98 (2) ◽  
pp. 199-211 ◽  
Author(s):  
E. M. Greitzer
Keyword(s):  
Quantitative Description ◽  
Axial Compressor ◽  
Axial Flow ◽  
Rotating Stall ◽  
Experimental Results ◽  
System Response ◽  
Physical Parameters ◽  
Geometrical Parameters ◽  
Compression System ◽  
Transient System

This paper reports an experimental study of axial compressor surge and rotating stall. The experiments were carried out using a three stage axial flow compressor. With the experimental facility the physical parameters of the compression system could be independently varied so that their influence on the transient system behavior can be clearly seen. In addition, a new data analysis procedure has been developed, using a plenum mass balance, which enables the instantaneous compressor mass flow to be accurately calculated. This information is coupled to the unsteady pressure measurements to provide the first detailed quantitative picture of instantaneous compressor operation during both surge and rotating stall transients. The experimental results are compared to a theoretical model of the transient system response. The theoretical criterion for predicting which mode of compression system instability, rotating stall or surge, will occur is in good accord with the data. The basic scaling concepts that have been developed for relating transient data at different corrected speeds and geometrical parameters are also verified. Finally, the model is shown to provide an adequate quantitative description of the motion of the compression system operating point during the transients that occur subsequent to the onset of axial compressor stall.

Surge and Rotating Stall in Axial Flow Compressors—Part I: Theoretical Compression System Model

1976 ◽  
Vol 98 (2) ◽  
pp. 190-198 ◽  
Author(s):  
E. M. Greitzer
Keyword(s):  
Pressure Ratio ◽  
Axial Compressor ◽  
Axial Flow ◽  
Oscillatory Behavior ◽  
Rotating Stall ◽  
Operating Conditions ◽  
Compression System ◽  
Compressor Surge ◽  
System Operating ◽  
Behavior Characteristic

This paper reports a theoretical study of axial compressor surge. A nonlinear model is developed to predict the transient response of a compression system subsequent to a perturbation from steady operating conditions. It is found that for the system investigated there is an important nondimensional parameter on which this response depends. Whether this parameter is above or below a critical value determines which mode of compressor instability, rotating stall or surge, will be encountered at the stall line. For values above the critical, the system will exhibit the large amplitude oscillatory behavior characteristic of surge; while for values below the critical it will move toward operation in rotating stall, at a substantially reduced flow rate and pressure ratio. Numerical results are presented to show the motion of the compression system operating point during these two basic modes of instability, and a physical explanation is given for the mechanism associated with the generation of surge cycle oscillations.

On the Determination of the Transfer Function of Infinite Line Pressure Probes for Turbomachinery Applications

2012 ◽  
Author(s):  
Nicolas Van de Wyer ◽  
Jean-François Brouckaert ◽  
Rinaldo L. Miorini
Keyword(s):  
Transfer Function ◽  
Frequency Response ◽  
Pressure Fluctuations ◽  
Axial Compressor ◽  
Fast Response ◽  
Experimental Results ◽  
Geometrical Parameters ◽  
Electrical Transmission ◽  
Infinite Line ◽  
Line Pressure

This paper deals with the use of the infinite line pressure probes (ILP) to measure fluctuating pressures in hot environments in turbomachinery applications. These probes, sometimes called waveguide measuring systems, and composed of a series of lines and cavities are using a remote pressure sensor. Ideally they should form a non-resonant system. This is however not always the case and the frequency response of these systems is of course limited by the tubing (diameter and length) but is also highly dependent on other geometrical parameters like sudden expansions or discontinuities in the tubing, or parasite cavities. The development of a new model for ILP simulation, based on the analogy between the propagation of the pressure waves in a line-cavity system and the electrical transmission line, is presented. Unlike the models based on the Bergh and Tijdeman equations, this approach allows the simulation of systems presenting parallel branches. This makes the model appropriate for the prediction of the frequency response of ILP. The model is validated by a comparison of the results with the theory of Bergh and Tijdeman, and with experimental results from the literature and from shock tube tests. Finally, the model is applied for the optimization of ILPs, representative of the systems used in the aeronautics industry, and compared to the experimental results performed on an axial compressor. In those tests, a typical ILP geometry is installed on the compressor casing to measure static pressure fluctuations in the rotor tip gap. Simultaneous measurements with a fast response flush-mounted sensor provided data for comparison and validation of the predicted transfer function.

Basic Features of Speed Induced Transient Behaviour of Axial Flow Compressors

1990 ◽  
Author(s):  
G. C. Tang
Keyword(s):  
Steady Flow ◽  
Time Lag ◽  
Axial Flow ◽  
Initial Point ◽  
Rotating Stall ◽  
Rate Of Change ◽  
Operating Point ◽  
System Response ◽  
Transient Behaviour ◽  
Basic Features

An investigation is presented of basic features of speed induced transient behaviours of axial compression system. A non–linear model is developed for prediction of the transient response due to speed variation. Generally, the operating point forms a loop during an accelerating process. A small B or great rate of change in speed leads to a large loop. In the hysteresis region of the characteristic of the compressor, there are four possible solutions: steady flow with the compressor working on the unstalled part of the characteristic; steady flow with the operating point first getting across the stall limit then going back to the initial point; rotating stall and surge. Two critical values of the B parameter are identified, on which the system response depends. They are: Br, at which transition from rotating stall to surge occurs, and Bs, at which that from surge to steady flow takes place. Br and Bs are found to vary with some factors concerned. Their variation with the initial point, rate of the change in speed and the time lag constant are also studied.

Separated Flows in Axial Flow Compressor With Variable Stator Vanes at Positive Incidence Angles

1994 ◽  
Author(s):  
Vaclav Cyrus
Keyword(s):  
Three Dimensional ◽  
Axial Compressor ◽  
Axial Flow ◽  
Separated Flow ◽  
Rotating Stall ◽  
Compressor Stage ◽  
Diffusion Factor ◽  
Stator Blade ◽  
Flow Compressor ◽  
End Wall

A detailed investigation of three-dimensional flow was carried out in a low speed rear axial compressor stage with the change of the stator blade row setting. The stator blade stagger change was in the range of (−14) – (23) degree. Measurements were performed by means of both stationary and rotating pressure probes at seven working points. The origin of large regions of separated flow in blade rows at positive incidence angles was analysed with the use of the spanwise diffusion factor distribution. These areas in the rotor and stator rows originated as the diffusion factor exceeded the critial value D = 0.6 within (1/4 – 1/3) of the blade height near one end-wall. The rotating stall in compressor stage arised when large regions of separated flow occured simultaneously in both rotor and stator blade rows.

scholarly journals A Wide-Range Axial-Flow Compressor Stage Performance Model

1992 ◽  
Author(s):  
Gregory S. Bloch ◽  
Walter F. O’Brien
Keyword(s):  
Axial Flow ◽  
Operating Conditions ◽  
System Response ◽  
Compressor Stage ◽  
Operating Characteristics ◽  
Compression System ◽  
Axial Flow Compressor ◽  
Multi Stage ◽  
Wide Range ◽  
Flow Compressor

Dynamic compression system response is a major concern in the operability of aircraft gas turbine engines. Multi-stage compression system computer models have been developed to predict compressor response to changing operating conditions. These models require a knowledge of the wide-range, steady-state operating characteristics as inputs, which has limited their use as predicting tools. The full range of dynamic axial-flow compressor operation spans forward and reversed flow conditions. A model for predicting the wide flow range characteristics of axial-flow compressor stages was developed and applied to a 3-stage, low-speed compressor with very favorable results and to a 10-stage, high-speed compressor with mixed results. Conclusions were made regarding the inception of stall and the effects associated with operating a stage in a multistage environment. It was also concluded that there are operating points of an isolated compressor stage that are not attainable when that stage is operated in a multi-stage environment.

scholarly journals Discussion: “Criteria for Spike Initiated Rotating Stall” (Vo, H. D., Tan, C. S., Greitzer, E. M., 2008, ASME J. Turbomach., 130, p. 011023)

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
A. Deppe ◽  
H. Saathoff ◽  
U. Stark
Keyword(s):  
Computational Study ◽  
Axial Flow ◽  
Leading Edge ◽  
Rotating Stall ◽  
Experimental Results ◽  
Leakage Flow ◽  
Tip Leakage Flow ◽  
Trailing Edge ◽  
Stall Inception ◽  
Tip Leakage

The paper “Criteria for Spike Initiated Rotating Stall” by Vo et al. (2008, ASME J. Turbomach., 130, p. 011023) provides a very important contribution to the understanding of spike-type stall inception in axial-flow compressors by demonstrating that spike-type disturbances are directly linked to the tip leakage flow of the rotor. The computational study of Vo et al. leads to the conclusion that two conditions have to be fulfilled simultaneously for the formation of spike-type stall: (i) axial backflow at the leading edge plane and (ii) axial backflow at the trailing edge plane. The objective of the present technical brief is to support these findings by corresponding experimental results.

Turbomachinery Committee Best 1994 Paper Award: Dynamic Control of Rotating Stall in Axial Flow Compressors Using Aeromechanical Feedback

1995 ◽  
Vol 117 (3) ◽  
pp. 307-319 ◽  
Author(s):  
D. L. Gysling ◽  
E. M. Greitzer
Keyword(s):  
Control Strategy ◽  
Dynamic Control ◽  
Axial Flow ◽  
Rotating Stall ◽  
Operating Conditions ◽  
Flow Coefficient ◽  
Compression System ◽  
Axial Flow Compressor ◽  
Flow Compressor ◽  
Axial Flow Compressors

Dynamic control of rotating stall in an axial flow compressor has been implemented using aeromechanical feedback. The control strategy developed used an array of wall jets, upstream of a single-stage compressor, which were regulated by locally reacting reed valves. These reed valves responded to the small-amplitude flow-field pressure perturbations that precede rotating stall. The valve design was such that the combined system, compressor plus reed valve controller, was stable under operating conditions that had been unstable without feedback. A 10 percent decrease in the stalling flow coefficient was obtained using the control strategy, and the extension of stable flow range was achieved with no measurable change in the steady-state performance of the compression system. The experiments demonstrate the first use of aeromechanical feedback to extend the stable operating range of an axial flow compressor, and the first use of local feedback and dynamic compensation techniques to suppress rotating stall. The design of the experiment was based on a two-dimensional stall inception model, which incorporated the effect of the aeromechanical feedback. The physical mechanism for rotating stall in axial flow compressors was examined with focus on the role of dynamic feedback in stabilizing compression system instability. As predicted and experimentally demonstrated, the effectiveness of the aeromechanical control strategy depends on a set of nondimensional control parameters that determine the interaction of the control strategy and the rotating stall dynamics.

Researches of Similitude Theory for Axial Flow Helium Compressor

2008 ◽  
Author(s):  
Rongkai Zhu ◽  
Qun Zheng ◽  
Guoqiang Yue ◽  
Jiguo Zou
Keyword(s):  
High Pressure ◽  
Axial Compressor ◽  
Axial Flow ◽  
Similarity Criterion ◽  
Physical Parameters ◽  
Adiabatic Exponent ◽  
Aerodynamic Design ◽  
Air Compressor ◽  
Accurate Design ◽  
Similitude Theory

In designing of a helium axial compressor from its homologous air compressor, the similarities between them have to be investigated. Such as how to establish the similarity criterion, how to prescribe the experimental air compressor’s parameters by the similitude laws, how to get the performance data of helium compressor from the air compressor test data etc, are important for the accurate design. The first stage of a high pressure helium compressor is taken as experimental model, with air as the working fluids in the experiments. The differences of physical parameters of helium and air, like density, viscosity, adiabatic exponent have been considered. The similitude laws used in the experiment have been established, and the reasons of deviation and correcting methods are analyzed. These results are useful references for the aerodynamic design of helium compressor.

Structural Dynamic Behavior of Axial Compressor Rotor

2017 ◽  
Author(s):  
Subramani Satish Kumar ◽  
Ranjan Ganguli ◽  
Siddanagouda Basanagouda Kandagal ◽  
Soumendu Jana
Keyword(s):  
Natural Frequencies ◽  
Axial Compressor ◽  
Axial Flow ◽  
Rotating Stall ◽  
Modal Identification ◽  
Mode Shapes ◽  
Stationary Condition ◽  
Structural Dynamic ◽  
Modal Characteristics ◽  
Compressor Rotor

The vibrations involved in a typical axial compressor rotor in an aircraft engine are complex. Generally, the compressor blades are arranged in a cantilever type configuration. It is also known that the amplitude of vibration is highest near the tip section of the shroudless blade. Compressors are limited by aerodynamic instabilities such as rotating stall and surge. Rotating stall generally initiates near the tip region of the compressor. Blade vibrations coupled with aerodynamic instabilities will lead to a catastrophic scenario of flutter that is asynchronous to the rotor speed. This aeroelastic interaction is detrimental if not taken into consideration. Knowledge of vibration characteristics of the compressor rotor will help in mapping the flutter zone for safe operation. The modal characteristics of the transonic axial compressor rotor available at the Axial Flow Compressor Research (AFCR) facility of National Aerospace Laboratories (NAL) are established in this study. A cyclic-symmetric pre-stressed modal analysis is performed on a single sector of the compressor rotor consisting of a shroudless blade connected to the disk with a pin type dovetail arrangement for different speeds. The main diagnostic charts for turbomachinery vibration i.e., Campbell and Interference diagrams are generated for various speeds and harmonic indices/ nodal diameters of the compressor rotor. The critical crossings of the engine order excitation lines over the natural frequencies of the blade are highlighted. Experimental modal investigations and analysis are carried out on the compressor rotor at the stationary condition and for two different boundary conditions. First, the blade alone modal characteristics under the free-free condition are established. Later, the complete blade-disk assembly mounted on a base test-stand is used to investigate the cantilever fixed-free boundary condition of the chosen blade. The modal characteristics are established by performing impact hammer experiments. Blade excitation is provided by a calibrated Dytran make impact hammer and the response is measured using a calibrated accelerometer. The structural dynamic data acquisition hardware and software from OROS is used for determining the natural frequencies, mode shapes and structural damping for each mode of the compressor rotor. There is a good agreement in the natural frequencies and mode shapes established using experiment and numerical methods for the first three modes investigated. Modal Assurance Criteria (MAC) analysis is carried out for two different modal identification algorithms to compare the mode shapes.

scholarly journals Improvement of Moderately Loaded Transonic Axial Compressor Performance Using Low Porosity Bend Skewed Casing Treatment

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Dilipkumar Bhanudasji Alone ◽  
S. Satish Kumar ◽  
Shobhavathy M. Thimmaiah ◽  
Janaki Rami Reddy Mudipalli ◽  
A. M. Pradeep ◽  
...  
Keyword(s):  
Axial Compressor ◽  
Axial Flow ◽  
Experimental Results ◽  
Compressor Stage ◽  
Stall Margin ◽  
Casing Treatment ◽  
Plenum Chamber ◽  
Chamber Volume ◽  
Maximum Improvement ◽  
Low Porosity

This paper presents experimental results of a single stage transonic axial flow compressor coupled with low porosity bend skewed casing treatment. The casing treatment has a plenum chamber above the bend slots. The depth of the plenum chamber is varied to understand its impact on the performance of compressor stage. The performance of the compressor stage is evaluated for casing treatment and plenum chamber configurations at two axial locations of 20% and 40%. Experimental results reveal that the stall margin of the compressor stage increases with increase in the plenum chamber volume. Hot-wire measurements show significant reduction in the turbulence intensity with increase in the plenum chamber volume compared to that with the solid casing at the stall condition. At higher operating speeds of 80% and at 20% axial coverage, the stall margin of the compressor increases by 20% with half and full plenum depth. The improvement in the peak stage efficiency observed is 4.6% with half plenum configuration and 3.34% with the full plenum configuration. The maximum improvement in the stall margin of 29.16% is obtained at 50% operating speed with full plenum configurations at 40% axial coverage.

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