Direct Force Wall Shear Measurements in Pressure-Driven Three-Dimensional Turbulent Boundary Layers

1982 ◽  
Vol 104 (2) ◽  
pp. 150-155 ◽  
Author(s):  
J. E. McAllister ◽  
F. J. Pierce ◽  
M. H. Tennant
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Three Dimensional ◽  
Turbulent Boundary Layers ◽  
Direct Measurements ◽  
Stress Directions ◽  
Wall Flow ◽  
Wall Shear ◽  
Pressure Driven

Unique, simultaneous direct measurements of the magnitude and direction of the local wall shear stress in a pressure-driven three-dimensional turbulent boundary layer are presented. The flow is also described with an oil streak wall flow pattern, a map of the wall shear stress-wall pressure gradient orientations, a comparison of the wall shear stress directions relative to the directions of the nearest wall velocity as measured with a typical, small boundary layer directionally sensitive claw probe, as well as limiting wall streamline directions from the oil streak patterns, and a comparison of the freestream streamlines and the wall flow streamlines. A review of corrections for direct force sensing shear meters for two-dimensional flows is presented with a brief discussion of their applicability to three-dimensional devices.

The Boundary-Layer Velocity Distribution in Turbulent Swirling Pipe Flow

1969 ◽  
Vol 91 (4) ◽  
pp. 728-733 ◽  
Author(s):  
R. G. Backshall ◽  
Fred Landis
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Three Dimensional ◽  
Axial Flow ◽  
Swirl Flow ◽  
Momentum Balance ◽  
Twisted Tape ◽  
Layer Velocity ◽  
Wall Shear

An experimental study was performed to determine the boundary-layer characteristics of an incompressible swirl flow produced by the insertion of a helically twisted tape into a pipe. The resulting flow can be approximated by a uniform axial flow with a superposed forced vortex flow. Boundary-layer velocity measurements indicate that the total velocity in this three-dimensional flow is well approximated by the universal logarithmic velocity profile. Modified axial and tangential logarithmic velocity laws have also been derived and are shown to be in good agreement with the data. The wall shear stress has to be determined either by direct velocity gradient measurements at the wall or by a modified momentum balance since pressure loss measurements do not directly lead to the correct wall shear stress.

Three-Dimensional Turbulent Boundary Layer in a Rotating Helical Channel

1975 ◽  
Vol 97 (2) ◽  
pp. 197-210 ◽  
Author(s):  
A. K. Anand ◽  
B. Lakshminarayana
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Turbulent Boundary Layer ◽  
Three Dimensional ◽  
Velocity Profiles ◽  
Layer Growth ◽  
Viscous Effects ◽  
Helical Channel ◽  
Wall Shear

An analytical and experimental investigation of the characteristics of a three-dimensional turbulent boundary layer in a rotating helical channel is reported in this paper. Expressions are developed for the velocity profiles in the inner layer, where the viscous effects dominate, and the outer layer, where the viscous effects are small. The prediction of boundary layer growth is based on the momentum integral technique. The analysis is valid for incompressible flow through a rotor blade row with small camber. The velocity profiles, wall shear stress and limiting streamline angles are measured inside the passages of a flat plate inducer at various radial and chordwise locations using rotating probes. The measurements are in general agreement with the predictions. Flow near the blade tip is found to be highly complex due to interaction of blade boundary layers and the annulus wall, resulting in appreciable radial inward flow as well as a defect in mainstream velocity near the midpassage. A wall shear stress correlation, which includes the effect of both Reynolds number and rotation parameter, is derived from the measured data.

Wall Shear Stress Inference From Two and Three-Dimensional Turbulent Boundary Layer Velocity Profiles

1973 ◽  
Vol 95 (1) ◽  
pp. 61-67 ◽  
Author(s):  
F. J. Pierce ◽  
B. B. Zimmerman
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Turbulent Boundary Layer ◽  
Velocity Profile ◽  
Three Dimensional ◽  
Law Of The Wall ◽  
Layer Velocity ◽  
Wall Shear ◽  
Near Wall

A method is developed to infer a local wall shear stress from a two-dimensional turbulent boundary layer velocity profile using all near-wall data with the Spalding single formula law of the wall. The method is used to broaden the Clauser chart scheme by providing for the inclusion of data in the laminar sublayer and transition region, as well as the data in the fully turbulent near-wall flow region. For a skewed velocity profile typical of pressure driven three-dimensional turbulent boundary layer flows, the method is extended to infer a wall shear stress for a three-dimensional turbulent boundary layer. Either wall shear stress or shear velocity values are calculated for two different sets of three-dimensional experimental data, with good agreement found between calculated and experimental results.

A Review of Near-Wall Similarity Models in Three-Dimensional Turbulent Boundary Layers

1983 ◽  
Vol 105 (3) ◽  
pp. 251-256 ◽  
Author(s):  
F. J. Pierce ◽  
J. E. McAllister ◽  
M. H. Tennant
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Boundary Layers ◽  
Force Measurement ◽  
Three Dimensional ◽  
Shear Velocity ◽  
Turbulent Boundary Layers ◽  
Velocity Relationship ◽  
Wall Shear ◽  
Near Wall

Eleven near-wall similarity models for three-dimensional turbulent boundary layers which have been identified in the literature are reviewed. Each model summary includes a brief review of its derivation, discusses limitations in the derivation, estimates the applicable y+ range, and compares differences among the models. This review of three-dimensional similarity models was developed as part of a larger study which tests the validity of ten of these different models by comparison with experimental data which includes the direct and simultaneous measurement of the local wall shear stress direction and magnitude in a three-dimensional turbulent flow. A direct force measurement of local wall shear stress is necessary to test the local wall shear-shear velocity relationship, τ0 = ρq*2, generally assumed in three-dimensional flows. This review is necessary to acquaint the reader with the similarities and differences among the models tested in companion papers since differences among some of the models are significant, particularly in the coordinate systems of the vector models.

Wall Shear Stress Inference for Three-Dimensional Turbulent Boundary-Layer Velocity Profiles

1976 ◽  
Vol 43 (1) ◽  
pp. 20-27 ◽  
Author(s):  
N. Chandrashekhar ◽  
N. V. C. Swamy
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Three Dimensional ◽  
Turbulent Boundary Layers ◽  
Wall Region ◽  
Stress Components ◽  
Layer Velocity ◽  
Wall Shear ◽  
Flow Similarity ◽  
Simplified Procedure

Based on flow similarity in the near-wall region of three-dimensional turbulent boundary layers, three methods have been developed for the prediction of the wall shear stress components, their resultant and its direction. The results from all the methods agree with one another and with available experimental results. It is found that the direction of the wall shear stress vector is not the same as the direction of the limiting wall streamline, except for small crossflows. A simplified procedure for estimating skin friction is also given, by which graphical work, as in the Clauser scheme, is eliminated.

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