Axisymmetrically Stalled Flow Performance for Multistage Axial Compressors

1986 ◽  
Vol 108 (2) ◽  
pp. 216-223 ◽  
Author(s):  
S. G. Koff ◽  
E. M. Greitzer
Keyword(s):  
Reasonable Agreement ◽  
Flow Model ◽  
Flow Characteristic ◽  
Pressure Rise ◽  
Rotating Stall ◽  
Two Dimensional ◽  
Reversed Flow ◽  
Axial Compressors ◽  
Point Pressure ◽  
Stagger Angle

A study of the stalled flow performance of multistage axial compressors is presented. A proposal is made regarding the form of axisymmetric pumping performance in stall (which is a requisite of current rotating stall models) over the entire compressor flow range, including reversed flow. It is also shown that the axisymmetric performance can rise above the measured stall point pressure rise, thus indicating greater unstalled pressure rise potential. A simple two-dimensional reversed flow model is presented, and is shown to be in reasonable agreement with available high backflow compressor data. The model predicts that the blade stagger angle greatly influences the reversed flow characteristic. Calculations are also carried out applying this axisymmetric characteristic to the rotating stall model of Moore.

scholarly journals Stalled Flow Performance for Axial Compressors: I — Axisymmetric Characteristic

1984 ◽  
Author(s):  
S. G. Koff ◽  
E. M. Greitzer
Keyword(s):  
Flow Model ◽  
Flow Characteristic ◽  
Pressure Rise ◽  
Rotating Stall ◽  
Reversed Flow ◽  
Axial Compressors ◽  
Point Pressure ◽  
Multistage Compressors ◽  
Entire Flow ◽  
Stagger Angle

A study of stalled flow performance of multistage compressors is presented. A new compressor characteristic is developed, describing the axisymmetric pumping performance over the entire compressor flow range, including reversed flow. This axisymmetric characteristic is required in any current rotating stall model. It is possible for the axisymmetric performance to rise above the measured stall point pressure rise, thus indicating greater unstalled pressure rise potential. In this context, the axisymmetric characteristic in forward flow is viewed as paralleling diffuser performance. A simple two-dimensional reversed flow model is presented, and is shown to be in reasonable agreement with available high backflow compressor data. The model predicts that the blade stagger angle greatly influences the reversed flow characteristic. Calculations are carried out using the rotating stall model of Moore and the axisymmetric characteristic developed herein, and a technique is suggested for estimating the axisymmetric curve over the entire flow range.

A Theory of Rotating Stall of Multistage Axial Compressors: Part I—Small Disturbances

1984 ◽  
Vol 106 (2) ◽  
pp. 313-320 ◽  
Author(s):  
F. K. Moore
Keyword(s):  
Pressure Rise ◽  
Propagation Speed ◽  
Rotating Stall ◽  
Flow Coefficient ◽  
Fluid Inertia ◽  
Flow Distortion ◽  
Axial Compressors ◽  
Experimental Values ◽  
Stagger Angle ◽  
Small Disturbances

An analysis is made of rotating stall in compressors of many stages, finding conditions under which a flow distortion can occur which is steady in a traveling reference frame, even though upstream total and downstream static pressure are constant. In the compressor, a pressure-rise hysteresis is assumed. Flow in entrance and exit ducts yield additional lags. These lags balance to give a formula for stall propagation speed. For small disturbances, it is required that the compressor characteristics be flat in the neighborhood of average flow coefficient. Results are compared with the experiments of Day and Cumpsty. If a compressor lag of about twice that due only to fluid inertia is used, predicted propagation speeds agree almost exactly with experimental values, taking into account changes of number of stages, stagger angle, row spacing, and number of stall zones. The agreement obtained gives encouragement for the extension of the theory to account for large amplitudes.

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.

A Three-Dimensional Unsteady Through-Flow Model for Rotating Stall in Axial Compressors

2020 ◽  
Author(s):  
Jin Guo ◽  
Jun Hu ◽  
Xuegao Wang ◽  
Rong Xu
Keyword(s):  
Flow Model ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Rotating Stall ◽  
Design Stage ◽  
Preliminary Evaluation ◽  
Source Terms ◽  
Axial Compressors ◽  
Through Flow

Abstract Rotating stall is a natural limit to the stable operating range of compressors due to the inverse pressure gradient of viscous gas. Effective prediction of compressor stall boundary is an important guarantee for the successful development of aeroengine. In this paper, a three-dimensional unsteady through-flow model based on body force theory is developed to reflect the dynamic stall process of multistage axial compressors with acceptable computational costs. The influence of blade geometric parameters is fully considered in blade force source terms. The source terms are related to the attack angle and Mach number of the blade inlet using the deviation angle and loss model in the through-flow theory. Meanwhile, the temporal lag response of the source terms to the upstream flow conditions is taken into account. Therefore, it can be utilized for predicting the off-design performance and rotating stall characteristics of multistage axial compressors. The developed model is validated on a two-stage low-speed axial compressor. The calculated performance line and stall cell speed are in agreement with the experimental results. The unsteady flow behavior of the compressor during stall is presented by the model. The results indicate that the developed model has the potential to be applied to the preliminary evaluation of compressor stability in design stage.

Influence of Rotating Instability on Stall Inception Patterns in a Variable-Pitch Axial-Flow Fan

2006 ◽  
Author(s):  
Takahiro Nishioka ◽  
Shuuji Kuroda ◽  
Tsukasa Nagano ◽  
Hiroshi Hayami
Keyword(s):  
Rotor Blade ◽  
Axial Flow ◽  
Pressure Rise ◽  
Leading Edge ◽  
Rotating Stall ◽  
Axial Flow Fan ◽  
Tip Leakage Vortex ◽  
Stall Inception ◽  
Tip Leakage ◽  
Stagger Angle

An experimental study was conducted to investigate the inception patterns of rotating stall at different rotor blade stagger-angle settings with the aim of extending the stable operating range for a variable-pitch axial-flow fan. Pressure and velocity fluctuations were measured for a low-speed axial-flow fan with a relatively large tip clearance. Two stagger-angle settings were tested, the design setting, and a high setting which was 10 degrees greater than the design setting. Rotating instability (RI) was first observed near the peak pressure-rise point at both settings. It propagated in the rotation direction at about 40 to 50% of the rotor rotation speed, and its wavelength was about one rotor-blade pitch. However, the stall-inception patterns differed between the two settings. At the design stagger-angle setting, leading edge separation occurred near the stall-inception point, and this separation induced a strong tip leakage vortex that moved upstream of the rotor. This leakage vortex simultaneously induced a spike and a RI. The conditions for stall inception were consistent with the simple model of the spike-type proposed by Camp and Day. At the high stagger-angle setting, leading edge separation did not occur, and the tip leakage vortex did not move upstream of the rotor. Therefore, a spike did not appear although RI developed at the maximum pressure-rise point. This RI induced a large end-wall blockage that extended into the entire blade passage downstream of the rotor. This large blockage rapidly increased the rotor blade loading and directly induced a long length-scale stall cell before a spike or modal disturbance appeared. The conditions for stall inception were not consistent with the simple models of the spike or modal-type. These findings indicate that the movement of the tip leakage vortex associated with the rotor blade loading affects the development of a spike and RI and that the inception pattern of a rotating stall depends on the stagger-angle setting of the rotor blades.

Numerical Simulation of Flow Instabilities in High Speed Multistage Compressors

2010 ◽  
Author(s):  
Huan Zhang ◽  
Jun Hu ◽  
Baofeng Tu ◽  
Zhiqiang Wang
Keyword(s):  
High Speed ◽  
Rotating Stall ◽  
Flow Instabilities ◽  
Two Dimensional ◽  
Duct Flow ◽  
Disk Model ◽  
Stall Inception ◽  
Axial Compressors ◽  
Multistage Compressors ◽  
The Stability

In the present paper, a nonlinear multi “actuator disk” model is proposed to analyze the dynamic behavior of flow instabilities, including rotating stall and surge, in high speed multistage axial compressors. The model describes the duct flow fields using two dimensional, compressible and unsteady Euler equations, and accounts for the influences of downstream plenum and throttle in the system as well. It replaces each blade row of multistage compressors with a disk. For numerical calculations, the time marching procedure, using MacCormack two steps scheme, is used. The main purpose of this paper is to predict the mechanism of two dimensional short wavelength rotating stall inception, the interaction between blade rows in high speed multistage compressors and the influence of rotating inlet distortion on the stability. It has been demonstrated that the model has the ability to predict those phenomena, and the results show that some system parameters have a strong effect on the stall features as well. Results for a five stage high speed compressor are analyzed in detail, and comparison with the experimental data demonstrates that the model and calculating results are reliable.

A theory for rotating stall in contra-rotating fans

2020 ◽  
pp. 095440622096253
Author(s):  
Hossein Khaleghi ◽  
Mohammad Javad Shahriyari ◽  
Martin Heinrich
Keyword(s):  
Single Cell ◽  
Critical Role ◽  
Pressure Rise ◽  
Transient Behavior ◽  
Rotating Stall ◽  
Speed Ratio ◽  
Rotor Speed ◽  
Modified Model ◽  
Stall Cells ◽  
Stagger Angle

This paper reports on a theory of rotating stall in contra-rotating fans and compressors. The theory is developed from Moore’s theory. A second-order hysteresis is used in the current study for the pressure rise of the counter-rotating rows. This enables the model to predict the transient behavior of the stall cell. Comparing the experimental results with the theory shows that the modified model can predict the speed of the stall cells fairly accurately. Results show that the rotor speed ratio plays a critical role in the stall cell speed and its direction of rotation. Furthermore, the developed model makes it possible to study the effects of stagger angle and number of stall cells. The conditions under which pure rotating stall can occur in contra-rotating fans are also discussed in this paper. It is shown that the stall cells merge to form a single cell before a stable fully-developed rotating stall is established.

Controls and Diagnostics Committee Best 1994 Paper Award: Modeling for Control of Rotating Stall in High-Speed Multistage Axial Compressors

1996 ◽  
Vol 118 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. R. Feulner ◽  
G. J. Hendricks ◽  
J. D. Paduano
Keyword(s):  
Transfer Function ◽  
Compressible Flow ◽  
Active Control ◽  
High Speed ◽  
Pressure Sensors ◽  
Rotating Stall ◽  
Two Dimensional ◽  
Input Output ◽  
Axial Compressors ◽  
Blade Row

Using a two-dimensional compressible flow representation of axial compressor dynamics, a control-theoretic input–output model is derived, which is of general utility in rotating stall/surge active control studies. The derivation presented here begins with a review of the fluid dynamic model, which is a two-dimensional stage stacking technique that accounts for blade row pressure rise, loss, and deviation as well as blade row and interblade row compressible flow. This model is extended to include the effects of the upstream and downstream geometry and boundary conditions, and then manipulated into a transfer function form that dynamically relates actuator motion to sensor measurements. Key relationships in this input–output form are then approximated using rational polynomials. Further manipulation yields an approximate model in standard form for studying active control of rotating stall and surge. As an example of high current relevance, the transfer function from an array of jet actuators to an array of static pressure sensors is derived. Numerical examples are also presented, including a demonstration of the importance of proper choice of sensor and actuator locations, as well as a comparison between sensor types. Under a variety of conditions, it was found that sensor locations near the front of the compressor or in the downstream gap are consistently the best choices, based on a quadratic optimization criterion and a specific three-stage compressor model. The modeling and evaluation procedures presented here are a first step toward a rigorous approach to the design of active control systems for high-speed axial compressors.

Sign in / Sign up

Export Citation Format

Share Document