scholarly journals Steady and Unsteady Three Dimensional Flow Field Downstream of an Embedded Stator in a Multistage Axial Flow Compressor: Part 3 — Deterministic Stress and Heat-Flux Distribution and Average-Passage Equation System

1998 ◽  
Author(s):  
N. Suryavamshi ◽  
B. Lakshminarayana ◽  
J. Prato
Keyword(s):  
Heat Flux ◽  
Flow Field ◽  
Three Dimensional ◽  
Tangential Velocity ◽  
Axial Flow ◽  
Equation System ◽  
Radial Component ◽  
Shear Stresses ◽  
Axial Flow Compressor ◽  
Flow Compressor

The results from the area traverse measurements of the unsteady velocity and total temperature downstream of the second stator of a three stage axial flow compressor have been correlated to derive various deterministic stress and heat-flux terms. These terms are consistent with those arising from the average-passage equation system of Adamczyk (1985). The deterministic periodic stress and heat-flux terms were found to be larger than the aperiodic terms for both the normal and shear components. Consequently the terms involving the aperiodic components in the average-passage equations could be neglected for stator exit and rotor inlet flow modeling. The deterministic periodic normal and shear stresses were seen to be most significant in the stator wakes away from the endwall regions. The most significant shear stress correlation was between the axial and tangential velocity components. Since the correlations involving the radial component were small, it is postulated that the dominant mechanism for mixing (in the radial direction) is due to the steady deterministic radial velocity. All three components of deterministic heat-flux were found to be significant in this flow field especially in the wakes. The dominant terms in the average-passage equation system away from the endwalls were due to the tangential gradient compared to the radial gradient terms and both the terms were found to be of equal importance in the hub and casing endwall regions.

scholarly journals Numerical Prediction of Wakes in Cascades and Compressor Rotors Including the Effects of Mixing: Part II — Rotor Passage Flow and Wakes Including the Effects of Spanwise Mixing

1991 ◽  
Author(s):  
N. Suryavamshi ◽  
B. Lakshminarayana
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Axial Flow ◽  
Radial Component ◽  
Navier Stokes ◽  
Mean Velocity ◽  
Compressor Rotor ◽  
Entire Flow ◽  
High Reynolds ◽  
Flow Compressor

The results of a numerical investigation to predict the flow field including wakes and mixing in axial flow compressor rotors has been presented in this paper. The wake behaviour in a moderately loaded compressor rotor has been studied numerically using a three-dimensional incompressible Navier-Stokes solver with a high Reynolds number form of the k–ε turbulence model. The equations are solved using a time dependent implicit technique. The agreement between the measured data and the predictions are good; including the blade boundary layer profiles, wake mean velocity profiles and decay. The ability of the pseudo-compressibility scheme to predict the entire flow field including the near and far wake profiles and its decay characteristics, effect of loading and the viscous losses of a three-dimensional rotor flow field has been demonstrated. An analysis of the passage averaged velocities and the pressure coefficients shows that the mixing in the downstream regions away from the hub and annulus walls is dominated by wake diffusion. In regions away from the walls, the radial mixing is predominantly caused by the transport of mass, momentum and energy by the radial component of velocity in the wake.

Numerical Prediction of Wakes in Cascades and Compressor Rotors Including the Effects of Mixing: Part II—Rotor Passage Flow and Wakes Including the Effects of Spanwise Mixing

1992 ◽  
Vol 114 (3) ◽  
pp. 617-626 ◽  
Author(s):  
N. Suryavamshi ◽  
B. Lakshminarayana
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Axial Flow ◽  
Radial Component ◽  
Navier Stokes ◽  
Mean Velocity ◽  
Compressor Rotor ◽  
Entire Flow ◽  
High Reynolds ◽  
Flow Compressor

The results of a numerical investigation to predict the flow field including wakes and mixing in axial flow compressor rotors has been presented in this paper. The wake behavior in a moderately loaded compressor rotor has been studied numerically using a three-dimensional incompressible Navier–Stokes solver with a high Reynolds number form of the k–ε turbulence model. The equations are solved using a time-dependent implicit technique. The agreement between the measured data and the predictions is good, including the blade boundary layer profiles, wake mean velocity profiles, and decay. The ability of the pseudocompressibility scheme to predict the entire flow field including the near and far wake profiles and its decay characteristics, effect of loading, and the viscous losses of a three-dimensional rotor flow field has been demonstrated. An analysis of the passage-averaged velocities and the pressure coefficients shows that the mixing in the downstream regions away from the hub and annulus walls is dominated by wake diffusion. In regions away from the walls, the radial mixing is predominantly caused by the transport of mass, momentum, and energy by the radial component of velocity in the wake.

scholarly journals Steady and Unsteady Three-Dimensional Flow Field Downstream of an Embedded Stator in a Multistage Axial Flow Compressor: Part 1 — Unsteady Velocity Field

1998 ◽  
Author(s):  
J. Prato ◽  
B. Lakshminarayana ◽  
N. Suryavamshi
Keyword(s):  
Velocity Field ◽  
Flow Field ◽  
Unsteady Flow ◽  
Three Dimensional ◽  
Axial Flow ◽  
High Response ◽  
Axial Flow Compressor ◽  
Flow Features ◽  
Flow Compressor ◽  
Hot Film

A comprehensive investigation of the three-dimensional unsteady flow and thermal field downstream of an embedded stator in a multistage compressor, acquired with a high-response hot-film probe and aspirating probe, is presented and analyzed. Some of the earlier data (five-hole probe and high-response Kulite probe) from the same compressor is used with the present data to provide an integrated and comprehensive interpretation of the flow and thermal fields. The emphasis is on the unsteady flow, unsteady thermal, and integrated flow fields. Part 1 covers the description of the facility and the development of the hot-film technique for multistage flow field measurement. In addition, the unsteady velocity field is presented and interpreted. Part 2 provides an integrated assessment of the stagnation pressure, temperature and velocity fields to derive a comprehensive understanding of the time-averaged flow features. The final part covers velocity-velocity and velocity-temperature correlations and the assessment of their magnitudes in the average-passage equations. The results from an area traverse of the unsteady velocity field derived from a 45 degree slanted film probe downstream of the second stator of a three-stage axial flow compressor are presented and discussed in this paper. The measurements were conducted at the peak efficiency operating point using a four-rotation method. The ensemble-averaged unsteady three-dimensional velocity data is resolved into the time-averaged component, revolution and blade periodic, and aperiodic components. Some of the features of the rotor 2 flow, measured at the exit of stator 2, reveal the extent of the spread of the upstream rotor wakes and the unsteadiness due to rotor hub and leakage flow regions and levels of periodic and aperiodic unsteadiness. Both the revolution and blade periodic velocity fluctuations are seen to be significantly greater than the aperiodic fluctuations.

scholarly journals Steady and Unsteady Three Dimensional Flow Field Downstream of an Embedded Stator in a Multistage Axial Flow Compressor: Part 2 — Composite Flow Field

1998 ◽  
Author(s):  
N. Suryavamshi ◽  
B. Lakshminarayana ◽  
J. Prato
Keyword(s):  
Flow Field ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Axial Flow ◽  
Flow Region ◽  
Suction Surface ◽  
Axial Flow Compressor ◽  
Composite Flow ◽  
Flow Compressor ◽  
Hot Film

In Part 1 of this paper, the unsteady velocity field derived from slanted hot-film measurements was presented and interpreted. In this part, the stagnation pressure (Kulite probe) and temperature data (Aspirating Probe) is integrated with the velocity data (hot-film probe) to derive a composite flow field description of the steady and unsteady flow behavior downstream of the second stator of a three stage axial flow compressor at the peak efficiency operating condition. Detailed mechanisms for various flow field features such as the hub clearance flow and the suction surface-casing endwall comer region have been analyzed based on the composite flow field. The feasibility of correlating the deterministic velocity and temperature distributions to develop stress and heat-flux terms to be used in Part 3 of this paper are explored. The results indicate that major blockage is caused in the stator hub endwall leakage flow and its possible subsequent rollup into a vortex and in the casing endwall region due to suction surface casing endwall comer and secondary flow region. These are also the regions with the highest levels of unsteadiness. From the ensemble averaged velocity, pressure and temperature field it was observed that very good comparison exists between these data sets for the wake properties such as width and depth. The transport of rotor wake towards the pressure side of the stator is confirmed through an integrated interpretation of all the flow properties.

Effects of Endwall Profiling on Axial Flow Compressor Stage

2009 ◽  
Author(s):  
Jialing Lu ◽  
Wuli Chu ◽  
Yanhui Wu
Keyword(s):  
Flow Field ◽  
Engineering Design ◽  
Axial Flow ◽  
Design Tool ◽  
Operating Conditions ◽  
Compressor Stage ◽  
Corner Separation ◽  
Axial Flow Compressor ◽  
Flow Compressor ◽  
Stage Efficiency

In recent years endwall profiling has been well validated as a major new engineering design tool for the reduction of secondary loss in turbines. However, its application on compressors have been rarely performed and reported. This paper documents the findings of the analysis for diminishing compressor stator corner separation using endwall profiling; In the study, novel profiled endwalls were designed and numerically studied on a subsonic axial-flow compressor stage. The compressor stator endwalls were profiled on both axial and azimuthal directions. The results showed, the stator corner separation was significantly suppressed under all the operating conditions by implementing this profiled endwall. Significant improvements on stage pressure ratios and stage efficiency were observed. Detailed flow field changes, as well as endwall profiling methods are provided in the paper, so that the results of this research can be referenced to other compressor designs.

Three-Dimensional Flow and Mixing in an Axial Flow Compressor With Different Rotor Tip Clearances

1992 ◽  
Vol 114 (3) ◽  
pp. 675-685 ◽  
Author(s):  
A. Goto
Keyword(s):  
Velocity Fluctuation ◽  
Three Dimensional ◽  
Axial Flow ◽  
Flow Fields ◽  
Tip Clearance ◽  
Small Scale ◽  
Three Dimensional Flow ◽  
Axial Flow Compressor ◽  
Dimensional Flow ◽  
Flow Compressor

The effect of difference in rotor tip clearance on the mean flow fields and unsteadiness and mixing across a stator blade row were investigated using hot-wire anemometry, pressure probes, flow visualization, and the ethylene tracer-gas technique on a single-stage axial flow compressor. The structure of the three-dimensional flow fields was discussed based on results of experiments using the 12-orientation single slanted hotwire technique and spectrum analysis of velocity fluctuation. High-pass filtered measurements of turbulence were also carried out in order to confirm small-scale velocity fluctuation, which is more realistically referred to as turbulence. The span-wise distribution of ethylene gas spreading, estimated by the measured small-scale velocity fluctuation at the rotor exit, agreed quite well with that which was experimentally measured. This fact suggests the significant role of turbulence, generated within the rotor, in the mixing process across the downstream stator. The value of the maximum mixing coefficient in the tip region was found to increase linearly as the tip clearance became enlarged, starting from the value at midspan.

scholarly journals Aerodynamic Analysis and Three-Dimensional Redesign of a Multi-Stage Axial Flow Compressor

Energies ◽  
2016 ◽  
Vol 9 (4) ◽  
pp. 296 ◽  
Author(s):  
Tao Ning ◽  
Chun-Wei Gu ◽  
Wei-Dou Ni ◽  
Xiao-Tang Li ◽  
Tai-Qiu Liu
Keyword(s):  
Three Dimensional ◽  
Axial Flow ◽  
Axial Flow Compressor ◽  
Aerodynamic Analysis ◽  
Multi Stage ◽  
Flow Compressor
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