1628 Numerical Analysis of Unsteady Flow Phenomena in an Axial Flow Compressor Rotor at Near Stall Condition

Measurements of the unsteady flow field over a rotor and within its wake are needed in the development of most turbomachines. The technique advocated is that of data acquisition by on-line computer, using the periodic passing of a blade as a phase reference. The phase-lock averaging process is described as is its use in reducing the noise of raw data traces. Measurements of the unsteady flow over a cascade and of the resulting boundary layer behavior are presented. The approach was used in interpreting the unsteady flow field of an axial-flow compressor rotor and the static pressure distribution over the rotor tip. Finally the application to centrifugal pumps is discussed, enabling the designer to obtain information on the suction pressures and the extent of any separated region.

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J051054 Effects of Tip Leakage Vortex Breakdown on Unsteady Flow Fields in an Axial Flow Compressor Rotor at Near-Stall Condition

The Proceedings of Mechanical Engineering Congress Japan ◽

10.1299/jsmemecj.2011._j051054-1 ◽

2011 ◽

Vol 2011 (0) ◽

pp. _J051054-1-_J051054-5

Author(s):

Hiroaki KIKUTA ◽

Kazutoyo YAMADA ◽

Satoshi Gunjishima ◽

Goki OKADA ◽

Yasunori HARA ◽

...

Keyword(s):

Unsteady Flow ◽

Vortex Breakdown ◽

Axial Flow ◽

Flow Fields ◽

Tip Leakage Vortex ◽

Tip Leakage ◽

Axial Flow Compressor ◽

Compressor Rotor ◽

Flow Compressor

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Numerical Investigation of Unsteady Flow Phenomena in an HP Axial Flow Compressor Incorporating Stator Shroud Cavities'

46th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit ◽

10.2514/6.2010-6532 ◽

2010 ◽

Cited By ~ 2

Author(s):

Tobias Froebel ◽

Hans-Peter Kau ◽

Christian Groth ◽

Volker Guemmer

Keyword(s):

Unsteady Flow ◽

Numerical Investigation ◽

Axial Flow ◽

Axial Flow Compressor ◽

Flow Phenomena ◽

Flow Compressor

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Large-Scale DES Analysis of Unsteady Flow Field in a Multi-Stage Axial Flow Compressor at Off-Design Condition Using K Computer

Volume 2C: Turbomachinery ◽

10.1115/gt2015-42648 ◽

2015 ◽

Cited By ~ 3

Author(s):

Kazutoyo Yamada ◽

Masato Furukawa ◽

Satoshi Nakakido ◽

Akinori Matsuoka ◽

Kentaro Nakayama

Keyword(s):

Boundary Condition ◽

Unsteady Flow ◽

Gas Turbines ◽

Large Scale ◽

Axial Flow ◽

Axial Flow Compressor ◽

Eddy Simulation ◽

Multi Stage ◽

Flow Phenomena ◽

Flow Compressor

The paper presents the results of large-scale numerical simulations which were conducted for better understanding of unsteady flow phenomena in a multi-stage axial flow compressor at off-design condition. The compressor is a test rig compressor which was used for development of the industrial gas turbine, Kawasaki L30A. The compressor consists of 14 stages, the front two stages and the front half stages of which were investigated in the present study. The final goal of this study is to elucidate the flow mechanism of the rotating stall inception in the multi-stage axial compressor for actual gas turbines, and according to the test data it is considered that the 2nd stage and the 5th or 6th stage are suspected of leading to the stall. In order to capture precise flow physics in the compressor, a computational mesh for the simulation was generated to have at least several million cells per passage, which amounted to 650 million cells for the front 2-stage simulation and two billion cells for the front 7-stage simulation (about three hundred million cells for each stage). Since these were still not enough for the large-eddy simulation (LES), the detached-eddy simulation (DES) was employed, which can calculate flow fields except near-wall region by LES. The required computational resources were quite large for such simulations, so the computations were conducted on the K computer (RIKEN AICS in Japan). The simulations were well validated, showing good agreement with the measurement results obtained in the test. In the validation, the effect of the boundary condition for the casing wall was also investigated by comparing the results between the adiabatic boundary condition and the isothermal boundary condition. As for the unsteady effect, the wake/blade interaction was investigated in detail. In addition, unsteady flow phenomena in the present compressor at off-design condition were analyzed by using data mining techniques such as vortex identification and limiting streamline drawing with the LIC (line integral convolution) method. The simulation showed that they could be caused by the corner separation on the hub side.

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A Study on Unsteady Flow Phenomena at Near-Stall in a Multi-Stage Axial Flow Compressor by Large-Scale DES with K Computer

International Journal of Gas Turbine, Propulsion and Power Systems ◽

10.38036/jgpp.9.1_18 ◽

2017 ◽

Vol 9 (1) ◽

pp. 18-26

Author(s):

Kazutoyo Yamada ◽

Masato Furukawa ◽

Satoshi Nakakido ◽

Yuki Tamura ◽

Akinori Matsuoka ◽

...

Keyword(s):

Unsteady Flow ◽

Large Scale ◽

Axial Flow ◽

Axial Flow Compressor ◽

Multi Stage ◽

Flow Phenomena ◽

Flow Compressor

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Effect of Circumferential Single Casing Groove Location on the Flow Stability under Tip-Clearance Effect in a Transonic Axial Flow Compressor Rotor

Energies ◽

10.3390/en14196143 ◽

2021 ◽

Vol 14 (19) ◽

pp. 6143

Author(s):

Xiaoxiong Wu ◽

Bo Liu ◽

Botao Zhang ◽

Xiaochen Mao

Keyword(s):

Control Mechanism ◽

Incidence Angle ◽

Axial Flow ◽

Flow Stability ◽

Tip Clearance ◽

Tip Leakage Flow ◽

Flow Angle ◽

Axial Flow Compressor ◽

Compressor Rotor ◽

Flow Compressor

Numerical simulations have been performed to study the effect of the circumferential single-grooved casing treatment (CT) at multiple locations on the tip-flow stability and the corresponding control mechanism at three tip-clearance-size (TCS) schemes in a transonic axial flow compressor rotor. The results show that the CT is more efficient when its groove is located from 10% to 40% tip axial chord, and G2 (located at near 20% tip axial chord) is the best CT scheme in terms of stall-margin improvement for the three TCS schemes. For effective CTs, the tip-leakage-flow (TLF) intensity, entropy generation and tip-flow blockage are reduced, which makes the interface between TLF and mainstream move downstream. A quantitative analysis of the relative inlet flow angle indicates that the reduction of flow incidence angle is not necessary to improve the flow stability for this transonic rotor. The control mechanism may be different for different TCS schemes due to the distinction of the stall inception process. For a better application of CT, the blade tip profile should be further modified by using an optimization method to adjust the shock position and strength during the design of a more efficient CT.

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Laser Anemometer Measurements in a Transonic Axial Flow Compressor Rotor

Journal of Engineering for Power ◽

10.1115/1.3230738 ◽

1981 ◽

Vol 103 (2) ◽

pp. 430-437 ◽

Cited By ~ 27

Author(s):

A. J. Strazisar ◽

J. A. Powell

Keyword(s):

Three Dimensional ◽

Axial Flow ◽

Compressor Rotor ◽

Laser Anemometer ◽

Flow Phenomena ◽

Conventional Instrumentation ◽

Efficient Data ◽

Shock System ◽

Flow Compressor ◽

Anemometer System

A laser anemometer system employing an efficient data acquisition technique has been used to make measurements upstream, within, and downstream of the compressor rotor. A fluorescent dye technique allowed measurements within endwall boundary layers. Adjustable laser beam orientation minimized shadowed regions and enabled radial velocity measurements outside of the blade row. The flow phenomena investigated include flow variations from passage to passage, the rotor shock system, three-dimensional flows in the blade wake, and the development of the outer endwall boundary layer. Laser anemometer measurements are compared to a numerical solution of the streamfunction equations and to measurements made with conventional instrumentation.

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Numerical Investigations of the Coupled Flow Through a Subsonic Compressor Rotor and Axial Skewed Slot

Journal of Turbomachinery ◽

10.1115/1.2948959 ◽

2008 ◽

Vol 131 (1) ◽

Cited By ~ 16

Author(s):

Xingen Lu ◽

Wuli Chu ◽

Junqiang Zhu ◽

Yangfeng Zhang

Keyword(s):

Axial Flow ◽

Tip Clearance ◽

Stall Margin ◽

Tip Clearance Flow ◽

Casing Treatment ◽

Axial Flow Compressor ◽

Compressor Rotor ◽

Clearance Flow ◽

Flow Through ◽

Flow Compressor

In order to advance the understanding of the fundamental mechanisms of axial skewed slot casing treatment and their effects on the subsonic axial-flow compressor flow field, the coupled unsteady flow through a subsonic compressor rotor and the axial skewed slot was simulated with a state-of-the-art multiblock flow solver. The computational results were first compared with available measured data, that showed the numerical procedure calculates the overall effect of the axial skewed slot correctly. Then, the numerically obtained flow fields were interrogated to identify the physical mechanism responsible for improvement in stall margin of a modern subsonic axial-flow compressor rotor due to the discrete skewed slots. It was found that the axial skewed slot casing treatment can increase the stall margin of subsonic compressor by repositioning of the tip clearance flow trajectory further toward the trailing of the blade passage and retarding the movement of the incoming∕tip clearance flow interface toward the rotor leading edge plane.

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Endwall Effects at Two Tip Clearances in a Multistage Axial Flow Compressor With Controlled Diffusion Blading

Journal of Turbomachinery ◽

10.1115/1.2929454 ◽

1994 ◽

Vol 116 (4) ◽

pp. 635-645 ◽

Cited By ~ 14

Author(s):

M. A. Howard ◽

P. C. Ivey ◽

J. P. Barton ◽

K. F. Young

Keyword(s):

Unsteady Flow ◽

Axial Flow ◽

Tip Clearance ◽

Exit Angle ◽

Controlled Diffusion ◽

The Third ◽

Flow Phenomena ◽

Multistage Compressor ◽

Flow Compressor ◽

Stage Efficiency

Effects of tip clearance, secondary flow, skew, and corner stall on the performance of a multistage compressor with controlled diffusion blading have been studied experimentally. Measurements between 1 and 99 percent annulus height were carried out in both the first and the third stages of a four-stage low-speed compressor with repeating-stage blading. Measurements were obtained at a datum rotor tip clearance and at a more aerodynamically desirable lower clearance. The consequences of the modified rotor tip clearance on both rotor and stator performance are examined in terms of loss coefficient and gas exit angle. Stator losses close to the casing are found to increase significantly when the clearance of an upstream rotor is increased. These increased stator losses cause 30 percent of the stage efficiency reduction that arises with increased rotor tip clearance. The deviation angles due to tip clearance from the multistage measurements are found to be similar to data from single-stage machines with conventional blading, which suggests that the unsteady flow phenomena associated with the multistage environment do not dominate the physics of the flow.

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