Steady and Unsteady Flow Field in a Multistage Low-Speed Axial Compressor: A Test Case

2008 ◽  
Author(s):  
Mario Ku¨nzelmann ◽  
Ralf Mu¨ller ◽  
Ronald Mailach ◽  
Konrad Vogeler
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Laser Doppler Anemometry ◽  
Guide Vane ◽  
Axial Compressor ◽  
Inlet Guide Vane ◽  
Test Case ◽  
Data Set ◽  
Low Speed ◽  
Blade Row

This paper introduces a new test case for compressor aerodynamics. The dataset is provided for the Dresden four-stage Low-Speed Research Compressor (LSRC), which was put into operation in 1995. The compressor consists of four identical stages, which are preceded by an inlet guide vane. The data set will be provided for the reference blading of the compressor with cantilevered stator vanes. This blading was developed on the basis of the profiles of a middle stage of a high-pressure compressor of a jet engine. This paper makes available the blading geometry as well as a variety of flow field measurement results. This includes the compressor map, selected pressure distributions and other results of flow field measurements with conventional techniques (e.g. Pitot probes, 5-hole probes). Furthermore different aspects of blade row interactions were addressed in this compressor within recent years. The periodical unsteady flow field within a selected rotor blade row was investigated using Laser-Doppler-Anemometry. Further results on the unsteady profile pressures and profile boundary layers will be provided. Supplementary, numerical results will be compared to the experiments. Results are available for several stages of the compressor and different operating points. With this test case a unique database for the aerodynamics in a multistage axial compressor will be provided that can be used for the validation of numerical codes.

The Influence of Wake–Wake Interactions on Loss Fluctuations of a Downstream Axial Compressor Blade Row

1998 ◽  
Vol 120 (4) ◽  
pp. 695-704 ◽  
Author(s):  
G. J. Walker ◽  
J. D. Hughes ◽  
I. Ko¨hler ◽  
W. J. Solomon
Keyword(s):  
Free Stream ◽  
Guide Vane ◽  
Axial Compressor ◽  
Inlet Guide Vane ◽  
Viscous Losses ◽  
Wake Interaction ◽  
Blade Row ◽  
Wake Interactions ◽  
Periodic Fluctuations ◽  
Disturbance Field

The interaction between wakes of an adjacent rotor–stator or stator–rotor blade row pair in an axial turbomachine is known to produce regular spatial variations in both the time-mean and unsteady flow fields in a frame relative to the upstream member of the pair. This paper examines the influence of such changes in the free-stream disturbance field on the viscous losses of a following blade row. Hot-wire measurements are carried out downstream of the outlet stator in a 1.5-stage axial compressor having equal blade numbers in the inlet guide vane (IGV) and stator rows. Clocking of the IGV row is used to vary the disturbance field experienced by the stator blades; the influence on stator wake properties is evaluated. The magnitude of periodic fluctuations in ensemble-averaged stator wake thickness is significantly influenced by IGV wake-rotor wake interaction effects. The changes in time-mean stator losses appear marginal.

Experimental and Numerical Researches in a Four-Stage Low Speed Research Compressor Facility

2020 ◽  
Author(s):  
Mingmin Zhu ◽  
Xiaoqing Qiang ◽  
Zhenzhou Ju ◽  
Yuchen Ma ◽  
Jinfang Teng
Keyword(s):  
Guide Vane ◽  
Axial Compressor ◽  
Internal Flow ◽  
Flow Fields ◽  
Inlet Guide Vane ◽  
External Diameter ◽  
Low Speed ◽  
Single Passage ◽  
Overall Performance ◽  
Inlet Conditions

Abstract The flow fields in rear stages of multi-stage axial compressor is difficult to measure in detail owing to the limited height and space. Thus, low speed research compressor (LSRC) facilities which are modelled from rear stages have been widely used to explore the internal flow fields and improve compressor design. A newly-designed vertical LSRC facility is established and put into used in Shanghai Jiao Tong University. The construction and design features of this LSRC facility are introduced in this paper. A cantilevered stage has been tested in this test rig. Compressor performance, inter-stage parameters distributions and contours are measured at design point and near stall point. Steady single passage simulations for four-stage compressor are carried out to validate numerical methods and further interpret the internal flow fields in test stages. This vertical LSRC facility consists of inlet guide vane (IGV) and four repeated stages with an external diameter of 1.5 meter and a rotating speed of 900 RPM. The third stage is the mainly tested one, while the first and second stages provide the inlet conditions and the fourth stage provides the outlet conditions. Complete measuring methods and systems are established for this newly-built LRSC facility. The measurements of overall performance and inter-stage flow fields are carried out for test stage with cantilevered stator rows. The simulation for four-stage compressor are also performed for cantilevered configuration. The results of steady single-passage simulation have a similar trend with experimental ones, in terms of overall performance and parameters distributions.

Periodical Unsteady Flow Within a Rotor Blade Row of an Axial Compressor: Part I — Flow Field at Midspan

2007 ◽  
Author(s):  
Ronald Mailach ◽  
Ingolf Lehmann ◽  
Konrad Vogeler
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Pressure Distribution ◽  
Rotor Blade ◽  
Laser Doppler Anemometry ◽  
Pressure Sensors ◽  
Stability Limit ◽  
Rotor Blades ◽  
Experimental Investigations ◽  
Blade Row

In this two-part paper results of the periodical unsteady flow field within the third rotor blade row of the four-stage Dresden Low-Speed Research Compressor are presented. The main part of the experimental investigations was performed using Laser-Doppler-Anemometry. Results of the flow field at several spanwise positions between midspan and rotor blade tip will be discussed. In addition time-resolving pressure sensors at midspan of the rotor blades provide information about the unsteady profile pressure distribution. In part I of the paper the flow field at midspan of the rotor blade row will be discussed. Different aspects of the blade row interaction process are considered for the design point and an operating point near the stability limit. The periodical unsteady blade-to-blade velocity field is dominated by the incoming stator wakes, while the potential effect of the stator blades is of minor influence. The inherent vortex structures and the negative jet effect, which is coupled to the wake appearance, are clearly resolved. Furthermore the time-resolved profile pressure distribution of the rotor blades is discussed. Although the negative jet effect within the rotor blade passage is very pronounced the rotor blade pressure distribution is nearly independent from the convectively propagating chopped stator wakes.

Periodical Unsteady Flow Within a Rotor Blade Row of an Axial Compressor—Part I: Flow Field at Midspan

2008 ◽  
Vol 130 (4) ◽  
pp. 041004 ◽  
Author(s):  
Ronald Mailach ◽  
Ingolf Lehmann ◽  
Konrad Vogeler
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Rotor Blade ◽  
Axial Compressor ◽  
Blade Row

scholarly journals IGV-Rotor Interactions in a 4-Stage Axial Compressor

1998 ◽  
Author(s):  
O. Puetz ◽  
J. Eikelmann ◽  
H. Stoff
Keyword(s):  
Flow Field ◽  
Total Pressure ◽  
Guide Vane ◽  
Axial Compressor ◽  
Suction Side ◽  
Fast Response ◽  
Operating Conditions ◽  
Inlet Guide Vane ◽  
Mean Values ◽  
Swirl Angle

Detailed experiments have been made in a 4-stage axial compressor of industrial design. The exit flow field of the rotor of the first stage was measured by hot-wire anemometry and fast-response pressure probes under design operating conditions. Tandem inlet guide vanes (IGV) are situated upstream of the first rotor. Flow field results are presented for total pressure, massflux and swirl angle over a closely-spaced grid of probe locations in radial and circumferential directions in the absolute and rotating frame of reference. The tandem inlet guide vane row and stage 1 vane row are positioned peripherally for various settings (clocking). Depending on the peripherical position of IGV and stator 1 the mean values for one rotor pitch varies by 1.5% for mass flow, 1.3° for swirl angle and 8.7% for total pressure. Loss in total pressure at the rotor exit is a minimum, when the IGV row wakes enter the downstream rotor passage at about 1/4 pitch from the suction-side. Blade and vane channels have similar pitchwise spacing.

The Influence of Rotor-Stator Spacing on the Loss in One-Stage Transonic Compressor

2009 ◽  
Author(s):  
Wan’ai Li ◽  
Yutao Sun ◽  
Yu-Xin Ren ◽  
Song Fu ◽  
Aspi R. Wadia
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Unsteady Flows ◽  
Axial Compressor ◽  
Test Case ◽  
Interesting Problem ◽  
Transonic Compressor ◽  
One Stage ◽  
Present Test ◽  
Gap Effects

The influence of axial spacing on the unsteady flow field and loss generation in the axial compressor is an important and interesting problem. In this paper, this influence is studied numerically by solving the 3D unsteady flows in a one-stage compressor consisting of NASA Rotor 35 and Stator 37 with three axial gaps in different sizes. The effect of axial spacing is discussed in terms of the adiabatic efficiency and the irreversibility. Numerical results indicate that smaller axial gap is favourable in reducing the irreversibility in the compressor of the present test case. A possible mechanism of the axial gap effects is presented.

Periodical Unsteady Flow Within a Rotor Blade Row of an Axial Compressor—Part II: Wake-Tip Clearance Vortex Interaction

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Ronald Mailach ◽  
Ingolf Lehmann ◽  
Konrad Vogeler
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Rotor Blade ◽  
Laser Doppler Anemometry ◽  
Pressure Sensors ◽  
Tip Clearance ◽  
Experimental Investigations ◽  
Blade Row ◽  
Blade Tip ◽  
Tip Clearance Vortex

In this two-part paper, results of the periodical unsteady flow field within the third rotor blade row of the four-stage Dresden low-speed research compressor are presented. The main part of the experimental investigations was performed using laser Doppler anemometry. Results of the flow field at several spanwise positions between midspan and rotor blade tip will be discussed. In addition, time-resolving pressure sensors at midspan of the rotor blades provide information about the unsteady profile pressure distribution. In Part II of the paper, the flow field in the rotor blade tip region will be discussed. The experimental results reveal a strong periodical interaction of the incoming stator wakes and the rotor blade tip clearance vortices. Consequently, in the rotor frame of reference, the tip clearance vortices are periodical with the stator blade passing frequency. Due to the wakes, the tip clearance vortices are separated into different segments. Along the mean vortex trajectory, these parts can be characterized by alternating patches of higher and lower velocities and flow turning or subsequent counter-rotating vortex pairs. These flow patterns move downstream along the tip clearance vortex path in time. As a result of the wake influence, the orientation and extension of the tip clearance vortices as well as the flow blockage periodically vary in time.

scholarly journals The Influence of Wake-Wake Interactions on Loss Fluctuations of a Downstream Axial Compressor Blade Row

1997 ◽  
Author(s):  
G. J. Walker ◽  
J. D. Hughes ◽  
I. Köhler ◽  
W. J. Solomon
Keyword(s):  
Free Stream ◽  
Guide Vane ◽  
Axial Compressor ◽  
Inlet Guide Vane ◽  
Viscous Losses ◽  
Wake Interaction ◽  
Blade Row ◽  
Wake Interactions ◽  
Periodic Fluctuations ◽  
Disturbance Field

The interaction between wakes of an adjacent rotor-stator or stator-rotor blade row pair in an axial turbomachine is known to produce regular spatial variations in both the time-mean and unsteady flow fields in a frame relative to the upstream member of the pair. This paper examines the influence of such changes in the free-stream disturbance field on the viscous losses of a following blade row. Hot-wire measurements are carried out downstream of the outlet stator in a 1.5-stage axial compressor having equal blade numbers in the inlet guide vane (IGV) and stator rows. Clocking of the IGV row is used to vary the disturbance field experienced by the stator blades: the influence on stator wake properties is evaluated. The magnitude of periodic fluctuations in ensemble-average stator wake thickness is significantly influenced by IGV wake-rotor wake interaction effects. The changes in time-mean stator losses appear marginal.

Influence of Inlet Guide Vane Wakes on the Passage Flow in a Transonic Axial Compressor

2012 ◽  
Author(s):  
S. Leichtfuss ◽  
C. Biela ◽  
H.-P. Schiffer ◽  
F. Heinichen
Keyword(s):  
Unsteady Flow ◽  
Guide Vane ◽  
Axial Compressor ◽  
Inlet Guide Vane ◽  
Tip Leakage ◽  
Transonic Compressor ◽  
Flow Phenomena ◽  
Unsteady Interaction ◽  
Current Article ◽  
Aero Engines

Variable inlet guide vanes enhance the efficiency and stability of modern transonic compressors. The current quest for compact and highly efficient aero-engines requires for higher stage-loading and small axial gaps between adjacent blade rows, increasing interaction between blade rows and introducing further unsteadiness into the flow. Modeling these interactions is relevant to jet engine implementation. Recent advancements in numerical simulation of unsteady flow in multiple blade rows create an additional way to investigate the flow patterns formed by the unsteady interaction. In the case of transonic compressors, the experimental and numerical database is small. The current article will contribute to this database by investigating the flow downstream of an inlet guide vane and the influence this flow has on the passage in a transonic compressor. Unsteady flow phenomena are resolved by piezoresistive wall pressure tappings. Numerical and experimental data show that the interaction of blade rows influences the formation of the tip leakage vortex. Analyzing the vortex structure within the transonic compressor stage it is possible to show how the blade rows interact and how geometric modifications in the VIGV tip gap model influence simulation results.

Unsteady Flow Around Suction Elbow and Inlet Guide Vanes in a Centrifugal Compressor

2004 ◽  
Author(s):  
Michael M. Cui
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Centrifugal Compressor ◽  
Guide Vane ◽  
Power Laws ◽  
Working Fluid ◽  
Inlet Guide Vane ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Compressor Design

A suction elbow and inlet guide vanes (IGVs) are typical upstream components in the front of the first-stage impeller in a centrifugal compressor. Since the flow field in the front of the impeller is subsonic, the flow motion induced by the rotating impeller interacts with the elbow and IGVs. These interactions induce turbulent unsteady flows inside compressors. The resulted unsteadiness affects efficiency, vibration, and noise generation of the compressor. To understand the mechanism controlling the interactions between up-steam components and to optimize the compressor design for better efficiency and reliability, the turbulent unsteady flow inside the first-stage of the compressor was simulated. The model includes the suction elbow, inlet guide vane housing, and first-stage impeller. HFC 134a was used as the working fluid. The thermodynamic and transport properties of the refrigerant gas were modeled by the Martin-Hou equation of state and power laws, respectively. The three-dimensional unsteady flow field was numerically simulated. The overall performance parameters were obtained by integrating the field quantities. The force, torque, and the arm of moments acting on the IGVs are then calculated. The results can be used to improve centrifugal compressor design to achieve higher efficiency and improve reliability.

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