Closure to “Discussion of ‘Mean Velocity and Decay Characteristics of the Near and Far-Wake of a Compressor Rotor Blade of Moderate Loading’” (1980, ASME J. Eng. Power, 102, pp. 547–548)

1980 ◽  
Vol 102 (3) ◽  
pp. 548-548
Author(s):  
A. Ravindranath ◽  
B. Lakshminarayana
Keyword(s):  
Rotor Blade ◽  
Mean Velocity ◽  
Compressor Rotor ◽  
Far Wake

Mean Velocity and Decay Characteristics of the Near- and Far-Wake of a Compressor Rotor Blade of Moderate Loading

1979 ◽  
Author(s):  
A. Ravindranath ◽  
B. Lakshminarayana
Keyword(s):  
Rotor Blade ◽  
Three Dimensional ◽  
Radial Component ◽  
Substantial Effect ◽  
Pressure Probe ◽  
Mean Velocity ◽  
Compressor Rotor ◽  
Spherical Head ◽  
The Mean ◽  
Far Wake

This paper reports the experimental study of the three-dimensional characteristics of the mean velocity in the wake of a moderately loaded compressor rotor blade. The measurements were taken with a three-sensor hot-wire probe rotating with the rotor. The wake was surveyed at several radial and axial stations. The loading was found to have substantial effect and this was reflected not only in the axial and tangential components, but also in the radial component. The radial velocities were found to be high very near the trailing-edge and this exhibits the characteristics prevalent in a trailing vortex system. The static pressures across the wake were measured using a direction insensitive spherical head static-stagnation pressure probe. The static pressure was found to be higher inside the wake. These and other measurements are reported and correlated in this paper.

Mean Velocity and Decay Characteristics of the Near and Far-Wake of a Compressor Rotor Blade of Moderate Loading

1980 ◽  
Vol 102 (3) ◽  
pp. 535-547 ◽  
Author(s):  
A. Ravindranath ◽  
B. Lakshminarayana
Keyword(s):  
Rotor Blade ◽  
Three Dimensional ◽  
Radial Component ◽  
Substantial Effect ◽  
Pressure Probe ◽  
Mean Velocity ◽  
Compressor Rotor ◽  
Spherical Head ◽  
The Mean ◽  
Far Wake

This paper reports the experimental study of the three-dimensional characteristics of the mean velocity in the wake of a moderately loaded compressor rotor blade. The measurements were taken with a three-sensor hot-wire probe rotating with the rotor. The wake was surveyed at several radial and axial stations. The loading was found to have substantial effect and this was reflected not only in the axial and tangential components, but also in the radial component. The radial velocities were found to be high very near the trailing-edge and this exhibits the characteristics prevalent in a trailing vortex system. The static pressures across the wake were measured using a direction insensitive spherical head static-stagnation pressure probe. The static pressure was found to be higher inside the wake. These and other measurements are reported and correlated in this paper.

Investigation of Compressor Rotor Wake Structure at Peak Pressure Rise Coefficient and Effects of Loading

1992 ◽  
Author(s):  
J. Prato ◽  
B. Lakshminarayana
Keyword(s):  
Radial Velocity ◽  
Decay Rate ◽  
Pressure Rise ◽  
Wall Region ◽  
Edge Region ◽  
Trailing Edge ◽  
Mean Velocity ◽  
Wake Structure ◽  
Compressor Rotor ◽  
Far Wake

This paper reports an experimental study of the three-dimensional characteristics of the mean velocity in the trailing-edge, near-wake and far-wake regions of a highly loaded low-speed compressor rotor. The wake structure and decay characteristics are compared with the wake data in the same compressor with moderate loading. The experimental investigation was carried out using a rotating five-hole probe. The flow field was surveyed at various radial and axial locations downstream of the compressor rotor. Variations in the axial, tangential and radial components of mean velocity at various axial and radial locations were derived from the data and compared with earlier data at lower loading to discern the effects of loading. It was found that the higher loading had the following effects: Higher total velocity defects were observed in the hub-wall region, increased wake growth rate in the tip region, faster decay of static pressure difference in the trailing-edge region, larger initial wake width in the trailing-edge region, increased rate of growth of the semi-wake width in the trailing-edge region, increased decay rate of radial velocity in the trailing-edge region and decreased decay rate of the radial velocity in the far-wake region. Far wake properties were almost identical in both cases.

Structure and Decay Characteristics of Turbulence in the Near and Far-Wake of a Moderately Loaded Compressor Rotor-Blade

1981 ◽  
Vol 103 (1) ◽  
pp. 131-140 ◽  
Author(s):  
A. Ravindranath ◽  
B. Lakshminarayana
Keyword(s):  
Rotor Blade ◽  
Guide Vane ◽  
Three Dimensional ◽  
Inlet Guide Vane ◽  
Near Wake ◽  
Trailing Edge ◽  
Free Stream Turbulence ◽  
Compressor Rotor ◽  
Wake Turbulence ◽  
Far Wake

The wake of a turbomachinery rotor-blade is turbulent, highly three-dimensional, and nonisotropic with appreciable curvature in the trailing-edge and near-wake regions. The characteristics of the turbulence vary considerably with radius, blade loading, free-stream turbulence, Reynolds number, and the rotor-blade geometry. This paper is concerned with the turbulence properties of a moderately loaded compressor blade, particularly near the blade trailing-edge. The tangential variation of the axial, tangential and radial intensities and stresses across the wake, as well as their decay characteristics were measured with a tri-axial hot-wire probe in the rotor frame of reference. The decay of intensities and stresses were found to be very rapid in the trailing-edge and near-wake regions and slow in the far-wake region. The effects of inlet-guide-vane and the hub-wall boundary layers on the rotor wake turbulence spectra are also discussed. Similarity rules for the three components of intensity are also derived and presented in this paper.

Investigation of Compressor Rotor Wake Structure at Peak Pressure Rise Coefficient and Effects of Loading

1993 ◽  
Vol 115 (3) ◽  
pp. 487-500 ◽  
Author(s):  
J. Prato ◽  
B. Lakshminarayana
Keyword(s):  
Radial Velocity ◽  
Decay Rate ◽  
Pressure Rise ◽  
Wall Region ◽  
Edge Region ◽  
Trailing Edge ◽  
Mean Velocity ◽  
Wake Structure ◽  
Compressor Rotor ◽  
Far Wake

This paper reports an experimental study of the three-dimensional characteristics of the mean velocity in the trailing-edge, near-wake, and far-wake regions of a highly loaded low-speed compressor rotor. The wake structure and decay characteristics are compared with the wake data in the same compressor with moderate loading. The experimental investigation was carried out using a rotating five-hole probe. The flow field was surveyed at various radial and axial locations downstream of the compressor rotor. Variations in the axial, tangential, and radial components of mean velocity at various axial and radial locations were derived from the data and compared with earlier data at lower loading to discern the effects of loading. It was found that the higher loading had the following effects: Higher total velocity defects were observed in the hub-wall region, increased wake growth rate in the tip region, faster decay of static pressure difference in the trailing-edge region, larger initial wake width in the trailing-edge region, increased rate of growth of the semi-wake width in the trailing-edge region, increased decay rate of radial velocity in the trailing-edge region, and decreased decay rate of the radial velocity in the far-wake region. Far wake properties were almost identical in both cases.

scholarly journals Aerodynamic Design and Testing of an Improved 1st Stage Compressor Rotor for a Heavy Duty Gas Turbine

1981 ◽  
Author(s):  
I. Ispas ◽  
H. J. Zollinger
Keyword(s):  
Gas Turbine ◽  
Rotor Blade ◽  
Aerodynamic Design ◽  
Heavy Duty ◽  
High Loss ◽  
Compressor Rotor ◽  
Performance Map ◽  
Computer Codes ◽  
Heavy Duty Gas Turbine ◽  
Design And Testing

To evaluate the potential of the compressor of Sulzer’s Typ 3 gas turbine, a series of engine tests was analyzed with two computer codes. The comparison between measured and calculated performance map are given in the paper. The design goal was to find modifications, which can be applied easily to already operating engines. The simplest option-increase of shaft speed with the existing blades-would have caused high loss due to increased tip Mach number. The calculation revealed, that a newly designed first rotor blade is an appropriate modification to increase massflow and efficiency. No further change is required, because the calculations indicate, that all subsequent stages operate at near optimum incidence. The calculations were confirmed experimentally. The paper presents the new rotor blade and its influence on the compressor calculated and measured performance.

scholarly journals Three-Dimensional Boundary Layer on a Compressor Rotor Blade at Peak Pressure Rise Coefficient

1986 ◽  
Author(s):  
B. Lakshminarayana ◽  
P. Popovski
Keyword(s):  
Boundary Layer ◽  
Rotor Blade ◽  
Peak Pressure ◽  
Pressure Coefficient ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Layer Growth ◽  
Leakage Flow ◽  
Suction Surface ◽  
Compressor Rotor

A comprehensive study of the three-dimensional turbulent boundary layer on a compressor rotor blade at peak pressure rise coefficient is reported in this paper. The measurements were carried out at various chordwise and radial locations on a compressor rotor blade using a rotating miniature “V” configuration hot-wire probe. The data are compared with the measurement at the design condition. Substantial changes in the blade boundary layer characteristics are observed, especially in the outer sixteen percent of the blade span. The increased chordwise pressure gradient and the leakage flow at the peak pressure coefficient have a cumulative effect in increasing the boundary layer growth on the suction surface. The leakage flow has a beneficial effect on the pressure surface. The momentum and boundary layer thicknesses increase substantially from those at the design condition, especially near the outer radii of the suction surface.

Cold Blade Profile Generation Methodology for Compressor Rotor Blades Using FSI Approach

2017 ◽  
Author(s):  
Kirubakaran Purushothaman ◽  
Sankar Kumar Jeyaraman ◽  
Ajay Pratap ◽  
Kishore Prasad Deshkulkarni
Keyword(s):  
Aspect Ratio ◽  
Rotor Blade ◽  
Axial Compressor ◽  
Operating Conditions ◽  
Rotor Blades ◽  
Blade Profile ◽  
Interaction Technique ◽  
Compressor Rotor ◽  
Blade Shape ◽  
Blade Geometry

This paper describes a methodology for obtaining correct blade geometry of high aspect ratio axial compressor blades during running condition taking into account of blade untwist and bending. It discusses the detailed approach for generating cold blade geometry for axial compressor rotor blades from the design blade geometry using fluid structure interaction technique. Cold blade geometry represents the rotor blade shape at rest, which under running condition deflects and takes a new operating blade shape under centrifugal and aerodynamic loads. Aerodynamic performance of compressor primarily depends on this operating rotor blade shape. At design point it is expected to have the operating blade shape same as the intended design blade geometry and a slight mismatch will result in severe performance deterioration. Starting from design blade profile, an appropriate cold blade profile is generated by applying proper lean and pre-twist calculated using this methodology. Further improvements were carried out to arrive at the cold blade profile to match the stagger of design profile at design operating conditions with lower deflection and stress for first stage rotor blade. In rear stages, thermal effects will contribute more towards blade deflection values. But due to short blade span, deflection and untwist values will be of lower values. Hence difference between cold blade and design blade profile would be small. This methodology can especially be used for front stage compressor rotor blades for which aspect ratio is higher and deflections are large.

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