Prediction of Compressor Performance in Rotating Stall

1978 ◽  
Vol 100 (1) ◽  
pp. 1-12 ◽  
Author(s):  
I. J. Day ◽  
E. M. Greitzer ◽  
N. A. Cumpsty
Keyword(s):  
Axial Velocity ◽  
Hysteresis Loops ◽  
Rotating Stall ◽  
Design Parameters ◽  
Heuristic Model ◽  
Axial Compressors ◽  
Large Hysteresis ◽  
Compressor Design ◽  
Compressor Performance ◽  
Design Value

A correlation is presented for predicting the performance characteristics of single and multistage axial compressors in rotating stall. The correlation is derived from new measurements of stalled compressor performance which have been obtained using a series of different compressor builds. In these experiments the compressor design parameters were systematically varied so that the influence of each could be clearly seen. It is shown that the stall cell blockage is an important parameter for correlating the flow regimes in stall, and hence the overall compressor performance. The resulting correlation, which has been developed based on a heuristic model of the stalled flow, can be applied to predict whether a given compressor will exhibit full-span or part-span stall, as well as the extent of the stall-unstall hysteresis loop. In particular, it is shown that as the number of stages and/or the design value of axial velocity parameter increases, the trend is toward both full-span stall and large hysteresis loops.

Impact of Rotor Wakes on Steady-State Axial Compressor Performance

1996 ◽  
Author(s):  
P. Deregel ◽  
C. S. Tan
Keyword(s):  
Steady State ◽  
Static Pressure ◽  
Axial Compressor ◽  
Pressure Rise ◽  
Initial Step ◽  
Inviscid Flow ◽  
Causal Link ◽  
Design Parameters ◽  
Compressor Design ◽  
Compressor Performance

This paper addresses the causal link first described by Smith between the unsteady flow induced by the rotor wakes and the compressor steady-state performance. As an initial step, inviscid flow in a compressor stage is examined. First of a kind numerical simulations are carried out to show that if the rotor wakes are mixed out after (as opposed to before) the stator passage, the time-averaged overall static pressure rise is increased and the mixing loss is reduced. An analytical model is also presented and shown to agree with the numerical results; the model is then used to examine the parametric trends associated with compressor design parameters.

Whirl Frequency Dependent Alford Forces in Axial Compressors

2004 ◽  
Author(s):  
Claus M. Myllerup ◽  
Graeme Keith
Keyword(s):  
Asymptotic Expansion ◽  
Axial Compressor ◽  
Cross Coupling ◽  
Coupling Model ◽  
Rotating Stall ◽  
Flow Dynamics ◽  
Mean Flow ◽  
Coupling Impedance ◽  
Axial Compressors ◽  
Compressor Design

Explicit closed form expressions are derived for the whirl frequency dependence of the Alford force in an axial compressor operating in steady-state away from the onset of rotating stall. The analysis includes the compressor flow dynamics using the Moore-Greitzer approximation. By asymptotic expansion in terms of the whirl orbit amplitude, expressions for the direct and cross-coupling impedance are obtained analytically. Several components in the cross-coupling impedance are shown to change phase as the whirl frequency transits the rotating stall frequency. This implies that for a given compressor design the Alford force can be stabilizing or destabilizing depending on flow rate and whirl frequency. Further, the analysis shows that the coupling between mean flow quantities and rotor whirl is of second order. Thereby, the present asymptotic expansion results in a fluid-structure coupling model, which is consistent in accuracy with usual linearized rotordynamic analysis.

The Effect of Wet Compression on a Multistage Subsonic Compressor

2013 ◽  
Vol 136 (3) ◽  
Author(s):  
Mingcong Luo ◽  
Qun Zheng ◽  
Lanxin Sun ◽  
Qingfeng Deng ◽  
Junjie Yang
Keyword(s):  
Working Condition ◽  
Pressure Ratio ◽  
Rotating Stall ◽  
Compression Effect ◽  
Flow Capacity ◽  
Compressor Design ◽  
Flow Field Characteristics ◽  
Compressor Performance ◽  
Dry And Wet Conditions ◽  
Wet Compression

In this paper, wet compression effect on an eight-stage axial subsonic compressor is simulated by steady numerical methods. Special attention is paid to the compressor design operating condition and rotating stall boundary to contrast and analyze the changes, such as the compressor performance and the flow-field characteristics under dry and wet conditions. The motions of water droplets are also simulated and analyzed. The results indicate that wet compression could weaken or eliminate the flow separation; improve the flow capacity, efficiency, and pressure ratio of this compressor; and make the compressor operating near the rotating stall boundary enter into the normal working condition.

Numerical Simulation of an Eight-Stage Axial Subsonic Compressor With Wet Compression

2013 ◽  
Author(s):  
Mingcong Luo ◽  
Qun Zheng ◽  
Lanxin Sun ◽  
Qingfeng Deng ◽  
Junjie Yang
Keyword(s):  
Working Condition ◽  
Pressure Ratio ◽  
Rotating Stall ◽  
Flow Capacity ◽  
Compressor Design ◽  
Flow Field Characteristics ◽  
Compressor Performance ◽  
Dry And Wet Conditions ◽  
Wet Compression ◽  
Compression Effects

In this paper, wet compression effects on an eight-stage axial subsonic compressor is simulated by steady numerical methods. Special attention is paid to the compressor design operating condition and rotating stall boundary to contrast and analyze the changes such as the compressor performance and the flow field characteristics under dry and wet conditions. The motions of water droplets are also simulated and analyzed. The results indicate that wet compression could weaken or eliminate the flow separation, improve the flow capacity, efficiency and pressure ratio of this compressor and make the compressor operating near the rotating stall boundary enter into the normal working condition.

Low Aspect Ratio Transonic Rotors: Part 1 — Baseline Design and Performance

1992 ◽  
Author(s):  
C. H. Law ◽  
A. R. Wadia
Keyword(s):  
Flow Analysis ◽  
Axial Flow ◽  
Test Point ◽  
Design Parameters ◽  
Design Study ◽  
Baseline Design ◽  
Design Variables ◽  
Compressor Design ◽  
Compressor Performance ◽  
And Performance

The analytical design and experimental test of a single-stage transonic axial-flow compressor are described. This design is the baseline of a compressor design study in which several blade design parameters have been systematically varied to determine their independent effects on compressor performance. The baseline design consisted of ruggedizing an existing compressor design, that demonstrated outstanding aerodynamic performance, to correct some undesirable aeromechanical characteristics. The design study was performed by varying only one design parameter at a time, keeping other design variables as close as possible to the baseline design. Specific design parameters of interest were those for which very little data was available to determine their sensitivity on compressor performance. This paper describes the baseline compressor design and its experimental performance. A detailed definition and flow analysis of the baseline design test point (used as the basis for all subsequent design variations) are provided.

Low Aspect Ratio Transonic Rotors: Part 1—Baseline Design and Performance

1993 ◽  
Vol 115 (2) ◽  
pp. 218-225 ◽  
Author(s):  
C. H. Law ◽  
A. R. Wadia
Keyword(s):  
Flow Analysis ◽  
Axial Flow ◽  
Test Point ◽  
Design Parameters ◽  
Design Study ◽  
Baseline Design ◽  
Design Variables ◽  
Compressor Design ◽  
Compressor Performance ◽  
Few Data

The analytical design and experimental test of a single-stage transonic axial-flow compressor are described. This design is the baseline of a compressor design study in which several blade design parameters have been systematically varied to determine their independent effects on compressor performance. The baseline design consisted of ruggedizing an existing compressor design that demonstrated outstanding aerodynamic performance, to correct some undesirable aeromechanical characteristics. The design study was performed by varying only one design parameter at a time, keeping the other design variables as close as possible to the baseline design. Specific design parameters of interest were those for which very few data were available to determine their sensitivity on compressor performance. This paper describes the baseline compressor design and its experimental performance. A detailed definition and flow analysis of the baseline design test point (used as the basis for all subsequent design variations) are provided.

Size and Reynolds Number Effects on Compressor Performance and Scaling

2020 ◽  
Author(s):  
Hua Chen
Keyword(s):  
Reynolds Number ◽  
Design Parameters ◽  
Test Results ◽  
Impeller Blade ◽  
Blade Number ◽  
Design Guide ◽  
Compressor Design ◽  
Reynolds Number Effects ◽  
Compressor Performance ◽  
Compressor Efficiency

Abstract Performance of small turbocharger compressors is greatly affected by their size and size related Reynolds number. Although the effect of Reynolds number on compressors’ efficiency is well known, the effects of Reynolds number have on other performance and design parameters of these compressors are little recognized in open literature. This paper reports the effects of Reynolds number and size on peak efficiency and surge flow of turbocharger compressors, studies the influences of Reynolds number on optimum compressor blade count. Test results show that when a compressor is scaled up (Reynolds number increases), its stability is generally reduced, and vice versa when scaled down. How this feature can be utilised in compressor design is discussed, and an example is given to show how compressor efficiency and flow range may be improved when scaling down by employing a more stable vaneless diffuser and reducing impeller blade number. Finally, the effect of Reynolds number on blade number selection for different sizes of a compressor is studied through CFD and test, and based on these experiences and the theory of flow on flat plate, a design guide line is proposed for the optimum blade numbers in compressor scaling for both impellers with and without splitter.

Endwall Blockage in Axial Compressors

1999 ◽  
Vol 121 (3) ◽  
pp. 499-509 ◽  
Author(s):  
S. A. Khalid ◽  
A. S. Khalsa ◽  
I. A. Waitz ◽  
C. S. Tan ◽  
E. M. Greitzer ◽  
...  
Keyword(s):  
Tip Clearance ◽  
Design Parameters ◽  
Tip Clearance Flow ◽  
Axial Compressors ◽  
Clearance Flow ◽  
Flow Features ◽  
Physical Insight ◽  
Level Loading ◽  
Stagger Angle ◽  
Insight Into

This paper presents a new methodology for quantifying compressor endwall blockage and an approach, using this quantification, for defining the links between design parameters, flow conditions, and the growth of blockage due to tip clearance flow. Numerical simulations, measurements in a low-speed compressor, and measurements in a wind tunnel designed to simulate a compressor clearance flow are used to assess the approach. The analysis thus developed allows predictions of endwall blockage associated with variations in tip clearance, blade stagger angle, inlet boundary layer thickness, loading level, loading profile, solidity, and clearance jet total pressure. The estimates provided by this simplified method capture the trends in blockage with changes in design parameters to within 10 percent. More importantly, however, the method provides physical insight into, and thus guidance for control of, the flow features and phenomena responsible for compressor endwall blockage generation.

Modeling of Discrete Tip Injection in a Two-Dimensional Streamline Curvature Method

2012 ◽  
Author(s):  
Roland Matzgeller ◽  
Richard Pichler
Keyword(s):  
Rotating Stall ◽  
Streamline Curvature ◽  
Measurement Results ◽  
Compressor Design ◽  
Multistage Compressor ◽  
Physical Effects ◽  
Tip Injection ◽  
Stability Enhancement ◽  
Good Agreement ◽  
Streamline Curvature Method

Fluid injection at the tip of highly loaded compressor rotors is known to be effective in suppressing the onset of rotating stall and eventually compressor instability. However, using such stability enhancement methods in a multistage compressor might not only stabilize certain stages but has also an impact on radial and axial matching. In order to account for tip injection during the early stages of compressor design, this paper focuses on the development of a method to model the physical effects underlying tip injection within a streamline curvature method. With the help of system identification it could be shown that a rotor subject to the discrete jets of tip injection adapts to the varying flow conditions according to a first order model. This information was used to generate a time-dependent input for the steady equations used with a streamline curvature method and eventually to model the unsteady response of the rotor to tip injection. Comparing the results obtained with the enhanced streamline curvature model to measurement results, good agreement could be shown which raised confidence that the influence of tip injection on axial and radial matching was sufficiently captured.

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