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

1994 ◽  
Vol 116 (4) ◽  
pp. 635-645 ◽  
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.

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

1993 ◽  
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 ◽  
Multi Stage ◽  
Flow Phenomena ◽  
Flow Compressor ◽  
Stage Efficiency

Effects of tip clearance, secondary flow, skew and corner stall on the performance of a multi-stage compressor with controlled diffusion blading have been studied experimentally. Measurements between 1% and 99% 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 consequence 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% of the stage efficiency reduction which arises with increased rotor tip clearance. The deviation angles due to tip clearance from the multi-stage 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 multi-stage environment do not dominate the physics of the flow.

A New Approach to the Experimental Study of Turbomachinery Flow Phenomena

1977 ◽  
Vol 99 (1) ◽  
pp. 97-105 ◽  
Author(s):  
J. P. Gostelow
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Axial Flow ◽  
Centrifugal Pumps ◽  
New Approach ◽  
Static Pressure Distribution ◽  
Compressor Rotor ◽  
Flow Phenomena ◽  
On Line ◽  
Flow Compressor

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.

scholarly journals Experimental Investigation of Rotor-Stator Interaction in Axial-Flow Turbines and Compressors

1998 ◽  
Vol 4 (4) ◽  
pp. 217-231
Author(s):  
Heinz E. Gallus
Keyword(s):  
Unsteady Flow ◽  
Total Pressure ◽  
Vector Fields ◽  
Guide Vane ◽  
Axial Flow ◽  
Tip Clearance ◽  
Inlet Guide Vane ◽  
Flow Measurements ◽  
Rotor Stator Interaction ◽  
Flow Compressor

Detailed results of unsteady flow measurements in a stator-rotor-stator assembly of an axial-flow turbine as well as an inlet guide vane-rotor-stator formation of an axial-flow compressor are presented in this paper.The measurements include the time-dependent 3-D velocity vector fields in the axial gaps between the blade rows by means of triple-hot wire-technique, furthermore the total pressure field downstream of the blade rows by means of semiconductor total pressure probes and the unsteady flow field determination in the rotor passages by LDV-technique. Special semiconductor pressure measurements along the casing all over the rotor tip clearance permit detailed discussion of the rotor tip clearance flows.The conclusion of the measured data provides a new and very instructive view of the physics of the unsteady blade-row interaction in axial-flow turbines and compressors.

Effects of tip clearance size on the unsteady flow behaviors and performance in a counter-rotating axial flow compressor

2017 ◽  
Vol 233 (3) ◽  
pp. 1059-1070 ◽  
Author(s):  
Xiaochen Mao ◽  
Bo Liu ◽  
Hang Zhao
Keyword(s):  
Unsteady Flow ◽  
Incidence Angle ◽  
Axial Flow ◽  
Leading Edge ◽  
Tip Clearance ◽  
Leakage Flow ◽  
Tip Leakage Flow ◽  
Tip Leakage ◽  
Axial Flow Compressor ◽  
Flow Compressor

This paper presents the studies performed to better understand the effects of increased tip clearance size on the unsteady flow behaviors and overall performance under the rotor–rotor interaction environment in a counter-rotating axial flow compressor. The investigation method is based on the three-dimensional unsteady Reynolds-averaged Navier–Stokes simulations. The results show that the intensified tip leakage flow in front rotor (R1) caused by the increased tip clearance size will lead to the growth of incoming incidence angle near the tip of the rear rotor (R2). The increasing of double leakage flow range plays a significant role in the sensitivity of the efficiency to tip clearance size and its extent is enlarged gradually with the increase of tip clearance size. As the tip clearance size is increased to 1.5τ (τ represents the designed tip clearance size) from 0.5τ, the results of the fast Fourier transform for the static pressure near blade tip show that two other new fluctuating frequency components appear due to the happening of tip leakage flow self-unsteadiness in R1 and R2, respectively. Additionally, the fluctuating strength near the tip in R2 is significantly increased. However, both the overall fluctuation in R1 caused by the potential effect from downstream and the oscillation in the hub corner on the pressure side of R2 are decreased obviously. The relative inflow angle tends to increase when the incoming wakes and tip leakage flow from R1 encounter the blade leading edge of R2, which leads to the result that the trajectory of tip leakage flow is shifted more upstream.

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

2015 ◽  
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.

Numerically Understand the Combined Effect of Tip Clearance and Circumferential Grooves Casing Treatment on the Performance of Single Stage Transonic Axial Flow Compressor

2015 ◽  
Author(s):  
Mitesh Goswami ◽  
Dilipkumar Bhanudasji Alone ◽  
Harish S. Choksi
Keyword(s):  
Axial Flow ◽  
Single Stage ◽  
Tip Clearance ◽  
Combined Effect ◽  
Stall Margin ◽  
Casing Treatment ◽  
Axial Flow Compressor ◽  
Circumferential Groove ◽  
Flow Compressor ◽  
Stage Efficiency

This paper deals with the numerical studies on the combined effect of tip clearance and axisymmetric circumferential grooves casing treatment (CGCT) on the overall performance and stall margin of a single stage transonic axial flow compressor. Steady state numerical analysis was carried out by solving three dimensional Reynolds-averaged-Navier-Stokes (RANS) Equations using the Shear Stress Transport (SST) k-ω Turbulence Model. The numerical stall inception point was identified from the last converged point by the convergence criteria, and the stall margin was numerically predicted. Additionally, the stall margin and the isentropic peak stage efficiencies of the circumferential casing grooves with various tip clearances were compared and evaluated in order to explore the influence of the tip clearance. Results obtained were compared with those obtained on the baseline compressor with the smooth casing (SC). Further computational studies were conducted to study the role of the tip leakage flow in axial compressor in triggering the stall. The relationship between the tip clearance flow, flow field and surge margin extension from circumferential groove casing treatment with various rotor tip clearances were studied numerically. The application of the circumferential groove casing treatment with varying clearance leads to significant improvement in the operating stability of compressor with slight reduction in the isentropic peak stage efficiency for small tip clearances, whereas there was slight increment in the isentropic peak stage efficiency at higher tip clearance of 2.5 mm.

The Influence of Shrouded Stator Cavity Flows on Multistage Compressor Performance

1999 ◽  
Vol 121 (3) ◽  
pp. 486-497 ◽  
Author(s):  
S. R. Wellborn ◽  
T. H. Okiishi
Keyword(s):  
Axial Flow ◽  
Pressure Rise ◽  
Tip Clearance ◽  
Cavity Flows ◽  
Suction Surface ◽  
Work Input ◽  
Tangential Momentum ◽  
Compressor Performance ◽  
Multistage Compressor ◽  
Flow Compressor

Experiments were performed on a low-speed multistage axial-flow compressor to assess the effects of shrouded stator cavity flows on aerodynamic performance. Five configurations, which involved systematic changes in seal-tooth leakage rates and/or elimination of the shrouded stator cavities, were tested. Rig data indicate increasing seal-tooth leakage substantially degraded compressor performance. For every 1 percent increase in seal-tooth clearance-to-span ratio, the decrease in pressure rise was 3 percent and the reduction in efficiency was 1 point. These observed performance penalties are comparable to those commonly reported for rotor and cantilevered stator tip clearance variations. The performance degradation observed with increased leakage was brought about in two distinct ways. First, increasing seal-tooth leakage directly spoiled the near-hub performance of the stator row in which leakage occurred. Second, the altered stator exit flow conditions, caused by increased leakage, impaired the performance of the next downstream stage by decreasing the work input of the rotor and increasing total pressure loss of the stator. These trends caused the performance of downstream stages to deteriorate progressively. Numerical simulations of the test rig stator flow field were also conducted to help resolve important fluid mechanic details associated with the interaction between the primary and cavity flows. Simulation results show that fluid originating in the upstream cavity collected on the stator suction surface when the cavity tangential momentum was low and on the pressure side when it was high. The convection of cavity fluid to the suction surface was a mechanism that reduced stator performance when leakage increased.

scholarly journals The Influence of Shrouded Stator Cavity Flows on Multistage Compressor Performance

1998 ◽  
Author(s):  
Steven R. Wellborn ◽  
Theodore H. Okiishi
Keyword(s):  
Axial Flow ◽  
Pressure Rise ◽  
Tip Clearance ◽  
Cavity Flows ◽  
Suction Surface ◽  
Work Input ◽  
Tangential Momentum ◽  
Compressor Performance ◽  
Multistage Compressor ◽  
Flow Compressor

Experiments were performed on a low-speed multistage axial-flow compressor to assess the effects shrouded stator cavity flows on aerodynamic performance. Five configurations, which involved systematic changes in seal-tooth leakage rates and/or elimination of the shrouded stator cavities, were tested. Rig data indicate increasing seal-tooth leakage substantially degraded compressor performance. For every 1% increase in seal-tooth clearance-to-span ratio the decrease in pressure rise was 3% and the reduction in efficiency was 1 point. These observed performance penalties are comparable to those commonly reported for rotor and cantilevered stator tip clearance variations. The performance degradation observed with increased leakage was brought about in two distinct ways. First, increasing seal-tooth leakage directly spoiled the near hub performance of the stator row in which leakage occurred. Second, the altered stator exit flow conditions, caused by increased leakage, impaired the performance of the next downstream stage by decreasing the work input of the rotor and increasing total pressure loss of the stator. These trends caused the performance of downstream stages to progressively deteriorate. Numerical simulations of the test rig stator flow field were also conducted to help resolve important fluid mechanic details associated with the interaction between the primary and cavity flows. Simulation results show that fluid originating in the upstream cavity collected on the stator suction surface when the cavity tangential momentum was low and on the pressure side when it was high. The convection of cavity fluid to the suction surface was a mechanism which reduced stator performance when leakage increased.

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

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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