Performance of Axial Compressor With Nonuniform Exit Static Pressure

1986 ◽  
Vol 108 (1) ◽  
pp. 76-81 ◽  
Author(s):  
H. Kodama
Keyword(s):  
Analytical Model ◽  
Analytical Method ◽  
Static Pressure ◽  
Axial Compressor ◽  
Two Dimensional ◽  
Pressure Perturbation ◽  
Disk Model ◽  
Axial Compressors ◽  
Actuator Disk ◽  
Good Agreement

An analytical model has been developed to predict the performance of axial compressors with an exit static pressure perturbation. The model uses a two-dimensional compressible semi-actuator disk model. This method can be applied to the compressor with known circumferential variation in exit static pressure which is measured or predicted by an analytical method. The analytical results are found to be in good agreement with experiments carried out on two transonic fans.

scholarly journals Performance of Axial Compressor With Non-Uniform Exit Static Pressure

1985 ◽  
Author(s):  
Hidekazu Kodama
Keyword(s):  
Analytical Method ◽  
Static Pressure ◽  
Axial Compressor ◽  
Analytic Model ◽  
Two Dimensional ◽  
Pressure Perturbation ◽  
Axial Compressors ◽  
Disc Model ◽  
Actuator Disc ◽  
Good Agreement

An analytic model has been developed to predict the performance of axial compressors with an exit static pressure perturbation. The model uses a two dimensional compressible semi-actuator disc model. This method can be applied to the compressor with known circumferential variation in exit static pressure which is measured or predicted by an analytical method. The analytical results are found to be in good agreement with experiments carried out on two transonic fans.

Investigations on Impulse Blade Cascades with Medium Deflection

1978 ◽  
Vol 100 (3) ◽  
pp. 432-438
Author(s):  
K. Bammert ◽  
B. Ahmadi
Keyword(s):  
Wind Tunnel ◽  
Axial Compressor ◽  
Two Dimensional ◽  
Axial Compressors ◽  
High Reaction ◽  
Multi Stage ◽  
Tandem Cascades

The transformation of energy in the stages of high-reaction axial compressors can be considerably increased if the rotor blading consists of tandem cascades. This also involves aerodynamically higher loading of the stator cascades deflecting the flow. The behavior of the base, mean, and tip sections impulse cascades of the stator of a multi-stage axial compressor designed on this basis was examined in a two-dimensional cascade wind tunnel. The results of these investigations are reported and discussed.

Chemical Nonequilibrium in Supersonic Nozzle Flow

1971 ◽  
Vol 93 (4) ◽  
pp. 576-586
Author(s):  
Roa-Ling Wang
Keyword(s):  
Static Pressure ◽  
Theoretical Study ◽  
Supersonic Nozzle ◽  
Reactive System ◽  
Nozzle Flow ◽  
Two Dimensional ◽  
Chemical Nonequilibrium ◽  
One Dimensional ◽  
Nonequilibrium Flows ◽  
Good Agreement

An experimental and theoretical study has been made on chemical nonequilibrium flows in a supersonic nozzle for a mixture of dissociated gases and inert diluent. In the calculations, four different flow behaviors were assumed: one-dimensional non-equilibrium, two-dimensional nonequilibrium, two-dimensional equilibrium, and two-dimensional frozen flows. These were compared with measurements of the static pressure and NO2 concentration in the supersonic nozzle flow of the NO2-N4O2-N2 reactive system. Relatively good agreement demonstrates the applicability of the proposed calculation methods and the validity of the assumed reaction mechanisms and their rate constants.

Wakes in Axial Compressors

1959 ◽  
Vol 63 (588) ◽  
pp. 730-731
Author(s):  
W. F. Wiles
Keyword(s):  
Constant Velocity ◽  
Static Pressure ◽  
Axial Compressor ◽  
Low Energy ◽  
Axial Compressors

The note in the July Journal by H. Pearson and A. B. McKenzie (p. 415) shows that the flow into an axial compressor is nearly at a constant velocity at all points in the entry plane; and that if a wake of low energy air is fed into it, the compressor reduces the static pressure locally in this wake, in such a way as to tend to preserve constant velocity over the whole face.

The Application of Actuator Disks to Calculations of the Flow in Turbofan Installations

1997 ◽  
Vol 119 (4) ◽  
pp. 733-741 ◽  
Author(s):  
W. G. Joo ◽  
T. P. Hynes
Keyword(s):  
Three Dimensional ◽  
Flow Fields ◽  
Experimental Results ◽  
Disk Model ◽  
Actuator Disk ◽  
Good Agreement

This paper discusses the application of an actuator disk model to the problem of calculating the asymmetric performance of a turbofan operating behind a nonaxisymmetric intake and due to the presence of the engine pylon. Good agreement between predictions and experimental results is demonstrated. Further validation of the model is obtained by comparison with the results of a three-dimensional calculation of an isolated fan operating with a nonaxisymmetric inlet. Some justification of the neglect of unsteady aspects of the flow in the fan is presented. The quantitative features of the interaction of the pylon and fan flow fields are discussed.

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.

Performance of Two Transonic Axial Compressor Rotors Incorporating Inlet Counterswirl

1987 ◽  
Vol 109 (1) ◽  
pp. 142-148 ◽  
Author(s):  
C. H. Law ◽  
A. J. Wennerstrom
Keyword(s):  
Static Pressure ◽  
Axial Compressor ◽  
Axial Flow ◽  
Leading Edge ◽  
Axial Compressors ◽  
Streamline Curvature ◽  
Static Pressure Distribution ◽  
Pressure Distributions ◽  
Blade Section ◽  
Flow Compressor

A single-stage axial-flow compressor which incorporates rotor inlet counterswirl to improve stage performance is discussed. Results for two rotor configurations are presented, including design and experimental test data. In this compressor design, inlet guide vanes were used to add counterswirl to the inlet of the rotor. The magnitude of the counterswirl was radially distributed to maximize the overall stage efficiency by minimizing the rotor combined losses (diffusion losses and shock losses). The shock losses were minimized by simultaneously optimizing the rotor blade section geometry, through-blade static pressure distribution, and leading edge aerodynamic/geometric shock sweep angles. Results from both the design and experimental performance analyses are presented and comparisons are made between the experimental data and the analyses and between the performance of both rotor designs. The computation of the flow field for both rotor designs and for the analysis of both tests was performed in an identical fashion using an axisymmetric, streamline-curvature-type code. Results presented include tip section blade-to-blade static pressure distributions and rotor through-blade and exit distributions of various aerodynamic parameters. The performance of this compressor stage represents a significant improvement in axial compressor performance compared to previous attempts to use rotor inlet counterswirl and to current, more conventional, state-of-the-art axial compressors operating under similar conditions.

Wakes in Axial Compressors

1959 ◽  
Vol 63 (583) ◽  
pp. 415-416 ◽  
Author(s):  
H. Pearson ◽  
A. B. McKenzie
Keyword(s):  
Static Pressure ◽  
Early Stage ◽  
Axial Compressor ◽  
Pressure Gradients ◽  
Blade Vibration ◽  
Axial Compressors ◽  
Pressure Distributions ◽  
The People ◽  
Total Head ◽  
Flow Test

The tendency in the past has been to assume that when wakes or non-uniform total head profiles are fed into an axial compressor then substantially constant static pressure prevails at the entry, the variations in total head appearing as variations in velocity. This variation in velocity causes variation in incidence on the early stage blade rows and thus can give rise to excitation of blade vibration. This assumption is implicit, for instance, in References 1 and 2, but we think has been a common assumption by most of the people working in this field.Where the compressor is fed by a duct of substantially parallel walls for a reasonable length ahead, such an assumption appeared justifiable. Such a duct when given an air flow test with its outlet discharging, for instance, to atmosphere instead of to the compressor, then the distribution assumed would normally be obtained and in fact many surveys of such ducts have been represented in this fashion. The object of this note is to show that, in fact, this distribution will not normally occur when the compressor is present and we may normally expect much more nearly a constant velocity into the compressor with attendant static pressure distributions to match with the total head variations ahead of the intake, with of course, the attendant curved flow to support the static pressure gradients.

scholarly journals Flowfield Calculation in Compressor Operating With Distorted Inlet Flow

1990 ◽  
Author(s):  
H. Joubert
Keyword(s):  
Euler Equations ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Blade Surface ◽  
Disk Model ◽  
Inlet Flow ◽  
Actuator Disk ◽  
Air Inlet ◽  
Surge Margin ◽  
Multistage Compressor

In order to improve the air inlet engine compatibility, SNECMA has carried out since several years an important effort to predict the effect of distorted inlet flow on compressor stability. Two different methods are developed: In the first one, the Euler equations are integrated in 2D blade to blade surface with a distorted inlet flow. This method is used to compare different profiles, in particular influence of the chord length is presented. In the second one, the aerodynamic behaviour of a multistage compressor operating in distorted inlet flow is calculated with a three dimensional method. This model is based on Euler equations resolution outside the rows. An actuator disk model is used to represent the response of the blade rows. The behaviour of a three stage axial compressor has been studied. The loss of surge margin and the pressure distortion transfer are compared with experimental data.

scholarly journals Performance of Two Transonic Axial Compressor Rotors Incorporating Inlet Counterswirl

1986 ◽  
Author(s):  
C. Herbert Law ◽  
Arthur J. Wennerstrom
Keyword(s):  
Static Pressure ◽  
Axial Compressor ◽  
Axial Flow ◽  
Leading Edge ◽  
Axial Compressors ◽  
Streamline Curvature ◽  
Static Pressure Distribution ◽  
Pressure Distributions ◽  
Blade Section ◽  
Flow Compressor

A single-stage axial-flow compressor which incorporates rotor inlet counterswirl to improve stage performance is discussed. Results for two rotor configurations are presented, including design and experimental test data. In this compressor design, inlet guide vanes were used to add counterswirl to the inlet of the rotor. The magnitude of the counterswirl was radially distributed to maximize the overall stage efficiency by minimizing the rotor combined losses (diffusion losses and shock losses). The shock losses were minimized by simultaneously optimizing the rotor blade section geometry, through-blade static pressure distribution, and leading edge aerodynamic/geometric shock sweep angles. Results from both the design and experimental performance analyses are presented and comparisons are made between the experimental data and the analyses and between the performances of both rotor designs. The computation of the flow field for both rotor designs and for the analysis of both tests was performed in an identical fashion using an axisymmetric, streamline-curvature-type code. Results presented include tip section blade-to-blade static pressure distributions and rotor through-blade and exit distributions of various aerodynamic parameters. The performance of this compressor stage represents a significant improvement in axial compressor performance compared to previous attempts to use rotor inlet counterswirl and to current, more conventional, state-of-the-art axial compressors operating under similar conditions.

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