Techniques for Aerodynamic and Turbulence Measurements in Turbomachinery Rotors

1981 ◽  
Vol 103 (2) ◽  
pp. 374-392 ◽  
Author(s):  
B. Lakshminarayana
Keyword(s):  
Data Transmission ◽  
Three Dimensional ◽  
Surface Measurement ◽  
Blade Surface ◽  
Flow Data ◽  
Reynolds Stresses ◽  
Hot Wire ◽  
Mean Velocity ◽  
Velocity Turbulence ◽  
Probe Measurements

The objective of this paper is to review the techniques employed for the measurement of flow in turbomachinery rotors. Only nonoptical techniques are included. Measurement of the following properties are covered: three-dimensional mean velocity, turbulence intensity and Reynolds stresses, static and stagnation pressures, and blade surface measurement. Both the conventional as well as the hot-wire/film techniques, including both the rotating- and the stationary-probe measurements, are reviewed. A brief description of various rotating-probe traverse mechanisms and rotor flow data transmission systems in use is also included.

An Explicit Non-Real Time Data Reduction Method of Triple Sensors Hot-Wire Anemometer in Three-Dimensional Flow

1988 ◽  
Vol 110 (2) ◽  
pp. 110-119 ◽  
Author(s):  
Y. T. Chew ◽  
R. L. Simpson
Keyword(s):  
Real Time ◽  
Three Dimensional ◽  
Computation Time ◽  
Reynolds Stresses ◽  
Hot Wire ◽  
Time Data ◽  
Three Dimensional Flow ◽  
Mean Velocity ◽  
Dimensional Flow ◽  
The Mean

An explicit non-real time method of reducing triple sensor hot-wire anenometer data to obtain the three mean velocity components and six Reynolds stresses, as well as their turbulence spectra in three-dimensional flow is proposed. Equations which relate explicitly the mean velocity components and Reynolds stresses in laboratory coordinates to the mean and mean square sensors output voltages in three stages are derived. The method was verified satisfactorily by comparison with single sensor hot-wire anemometer measurements in a zero pressure gradient incompressible turbulent boundary layer flow. It is simple and requires much lesser computation time when compared to other implicit non-real time method.

A Method of Measuring the Three-Dimensional Mean Flow and Turbulence Quantities Inside a Rotating Turbo-machinery Passage

1976 ◽  
Vol 98 (2) ◽  
pp. 137-144 ◽  
Author(s):  
C. A. Gorton ◽  
B. Lakshminarayana
Keyword(s):  
Turbulence Intensity ◽  
Three Dimensional ◽  
Hot Wire ◽  
Mean Flow ◽  
Mean Velocity ◽  
Hot Wire Anemometry ◽  
Turbo Machinery ◽  
Velocity Turbulence

A method of measuring the three-dimensional components of mean velocity and turbulence quantities within a rotating turbomachinery passage is developed through the use of hot wire anemometry techniques. Equations are derived which, when solved simultaneously and in conjunction with the data obtained from the hot wire anemometer measurements, will provide values for the radial, axial and tangential components of mean velocity, turbulence intensity and turbulence stress within the rotating turbomachinery passage. A three-bladed rocket pump inducer model, operating in air, was used in the experimentation. The method is very accurate and provides very useful information on the characteristics of the flow inside rotor passages hitherto unexplored.

Turbulence Measurements Near the Stern of a Ship Model

1984 ◽  
Vol 28 (03) ◽  
pp. 186-201
Author(s):  
Lennart Löfdahl ◽  
Lars Larsson
Keyword(s):  
Boundary Layer ◽  
Strong Influence ◽  
Three Dimensional ◽  
Reynolds Stresses ◽  
Hot Wire ◽  
Calculation Methods ◽  
Mean Velocity ◽  
Ship Model ◽  
The Mean ◽  
Stress Profiles

An experimental investigation in which Reynolds stress profiles were measured in the thick three-dimensional turbulent boundary layer at the stern of a ship model has been carried out. The measurements were performed using a specially developed hot-wire technique in which the mean velocity component perpendicular to the surface was considered. A large number of results are given in diagrams, and an error estimation for the different Reynolds stresses is presented. Efforts have been made, when positioning the measured turbulence profiles, to enable future development of calculation methods based on these results. The measured profiles have revealed a strong influence of streamline convergence (divergence) on the Reynolds stresses. Also, the effects of wall curvature are of importance, and since most parts of the investigated region have a convex curvature the average level of the stresses is reduced.

Hot Wire Measurements at the Exit of a Centrifugal Compressor Impeller

1979 ◽  
Vol 193 (1) ◽  
pp. 341-347
Author(s):  
A. Goulas ◽  
R. C. Baker
Keyword(s):  
Centrifugal Compressor ◽  
Magnetic Tape ◽  
Reynolds Stresses ◽  
Hot Wire ◽  
Mean Velocity ◽  
Isentropic Flow ◽  
Compressor Impeller ◽  
The Mean

Hot wire measurements at the exit of a small centrifugal compressor impeller are reported. Three different hot wire readings were obtained and stored on a magnetic tape for each point by gating the analogue hot wire signal with a pulse which indicated circumferential position. The combination of the three readings yielded the mean velocity and some Reynolds stresses at each point. The measurements show a ‘jet-wake’ profile towards the shroud and ‘isentropic’ flow near the hub.

Some measurements in the self-preserving jet

1969 ◽  
Vol 38 (3) ◽  
pp. 577-612 ◽  
Author(s):  
I. Wygnanski ◽  
H. Fiedler
Keyword(s):  
Low Frequency ◽  
Convection Velocity ◽  
Hot Wire ◽  
Frequency Range ◽  
Mean Velocity ◽  
Frequency Spectra ◽  
Velocity Fluctuations ◽  
Taylor’S Hypothesis ◽  
Velocity Turbulence ◽  
Made In

The axisymmetric turbulent incompressible and isothermal jet was investigated by use of linearized constant-temperature hot-wire anemometers. It was established that the jet was truly self-preserving some 70 diameters downstream of the nozzle and most of the measurements were made in excess of this distance. The quantities measured include mean velocity, turbulence stresses, intermittency, skewness and flatness factors, correlations, scales, low-frequency spectra and convection velocity. The r.m.s. values of the various velocity fluctuations differ from those measured previously as a result of lack of self-preservation and insufficient frequency range in the instrumentation of the previous investigations. It appears that Taylor's hypothesis is not applicable to this flow, but the use of convection velocity of the appropriate scale for the transformation from temporal to spatial quantities appears appropriate. The energy balance was calculated from the various measured quantities and the result is quite different from the recent measurements of Sami (1967), which were obtained twenty diameters downstream from the nozzle. In light of these measurements some previous hypotheses about the turbulent structure and the transport phenomena are discussed. Some of the quantities were obtained by two or more different methods, and their relative merits and accuracy are assessed.

Experimental Investigation of a Free Round Jet with Dean Vortices

2014 ◽  
Vol 9 (2) ◽  
pp. 128-135
Author(s):  
Maria Litvinenko ◽  
Yuriy Litvinenko ◽  
Grigory Kozlov ◽  
Valentin Vikhorev
Keyword(s):  
Experimental Investigation ◽  
Three Dimensional ◽  
Experimental Investigations ◽  
Acoustic Excitation ◽  
Hot Wire ◽  
Curved Channel ◽  
Mean Velocity ◽  
Round Jet ◽  
Smoke Visualization ◽  
Dean Vortices

Results of the experimental investigations of free round jet with Dean vortices formed in curved channel are presented. Hot-wire anemometry measurements of three-dimensional mean velocity profile were performed, smoke visualization pictures cross and longitudinal sections at nozzle exit and downstream were obtained. The features of jet development at acoustic excitation of 40 Hz are shown

Measurement of the Reynolds stresses and the mean-flow field in a three-dimensional pressure-driven boundary layer

1982 ◽  
Vol 119 ◽  
pp. 121-153 ◽  
Author(s):  
Udo R. Müller
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Flow Field ◽  
Three Dimensional ◽  
Turbulent Shear ◽  
Reynolds Stresses ◽  
Mean Flow ◽  
Mean Velocity ◽  
Flow Acceleration ◽  
The Mean

An experimental study of a steady, incompressible, three-dimensional turbulent boundary layer approaching separation is reported. The flow field external to the boundary layer was deflected laterally by turning vanes so that streamwise flow deceleration occurred simultaneous with cross-flow acceleration. At 21 stations profiles of the mean-velocity components and of the six Reynolds stresses were measured with single- and X-hot-wire probes, which were rotatable around their longitudinal axes. The calibration of the hot wires with respect to magnitude and direction of the velocity vector as well as the method of evaluating the Reynolds stresses from the measured data are described in a separate paper (Müller 1982, hereinafter referred to as II). At each measuring station the wall shear stress was inferred from a Preston-tube measurement as well as from a Clauser chart. With the measured profiles of the mean velocities and of the Reynolds stresses several assumptions used for turbulence modelling were checked for their validity in this flow. For example, eddy viscosities for both tangential directions and the corresponding mixing lengths as well as the ratio of resultant turbulent shear stress to turbulent kinetic energy were derived from the data.

Experimental investigation of jets in a crossflow

1984 ◽  
Vol 138 ◽  
pp. 93-127 ◽  
Author(s):  
J. Andreopoulos ◽  
W. Rodi
Keyword(s):  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Velocity Ratio ◽  
Three Dimensional ◽  
Turbulent Shear ◽  
Shear Stresses ◽  
Hot Wire ◽  
Mean Flow ◽  
Mean Velocity ◽  
Turbulent Kinetic Energy Equation

The paper reports on measurements in the flow generated by a jet issuing from a circular outlet in a wall into a cross-stream along this wall. For the jet-to-crossflow velocity ratios R of 0.5, 1 and 2, the mean and fluctuating velocity components were measured with a three-sensor hot-wire probe. The hot-wire signals were evaluated to yield the three mean-velocity components, the turbulent kinetic energy, the three turbulent shear stresses and, in the case of R = 0.5, the terms in the turbulent-kinetic-energy equation. The results give a quantitative picture of the complex three-dimensional mean flow and turbulence field, and the various phenomena as well as their dependence on the velocity ratio R are discussed in detail.

Reynolds Stresses and Dissipation Mechanisms Downstream of a Turbine Cascade

1987 ◽  
Vol 109 (2) ◽  
pp. 258-267 ◽  
Author(s):  
J. Moore ◽  
D. M. Shaffer ◽  
J. G. Moore
Keyword(s):  
Kinetic Energy ◽  
Large Scale ◽  
Three Dimensional ◽  
Turbulent Shear ◽  
Shear Stresses ◽  
Turbine Cascade ◽  
Reynolds Stresses ◽  
Mean Velocity ◽  
Redundant Data ◽  
Fitting Procedures

An experimental investigation was performed to measure Reynolds stresses in the turbulent flow downstream of a large-scale linear turbine cascade. A rotatable X-wire hot-wire probe that allows redundant data to be taken with solution for mean velocities and turbulence quantities by least-squares fitting procedures was developed. The rotatable X-wire was used to obtain the Reynolds stresses on a measurement plane located 10 percent of an axial chord downstream of the trailing edge. Here the turbulence kinetic energy exhibits a distribution resembling the contours of total pressure loss obtained previously, but is highest in the blade wake where losses are relatively low. The turbulent shear stresses obtained are consistent in sign and magnitude with the gradients of mean velocity. The measured Reynolds stresses are combined with measured distributions of velocity to show how and where losses are being produced. The mechanisms for the dissipation of mean kinetic energy in this swirling three-dimensional flow are revealed.

A fast simple hot-wire method of determining the mean velocity vector of complex three-dimensional flows

1996 ◽  
Vol 20 (5) ◽  
pp. 398-400 ◽  
Author(s):  
L. Löfdahl ◽  
B. Johansson ◽  
C. Ljus ◽  
P. Ålleving
Keyword(s):  
Velocity Vector ◽  
Three Dimensional ◽  
Hot Wire ◽  
Mean Velocity ◽  
Wire Method ◽  
The Mean
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