Author: J. P. Johnston
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 62
Book Description
The various methods for measurement of the six components of the turbulence stress tensor are reviewed, and some of the data on the turbulent shear stress vector are presented to demonstrate the validity of current ideas for.
Experimental Studies in Three-dimensional Turbulent Boundary Layers
Author: J. P. Johnston
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 62
Book Description
The various methods for measurement of the six components of the turbulence stress tensor are reviewed, and some of the data on the turbulent shear stress vector are presented to demonstrate the validity of current ideas for.
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 62
Book Description
The various methods for measurement of the six components of the turbulence stress tensor are reviewed, and some of the data on the turbulent shear stress vector are presented to demonstrate the validity of current ideas for.
Experimental Studies of a Two and a Three-dimensional Low Speed Turbulent Boundary Layer
Author: Allen Edward Winkelmann
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 700
Book Description
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 700
Book Description
Three-dimensional Turbulent Boundary Layers
Author: O. Sendstad
Publisher:
ISBN:
Category : Simulation methods
Languages : en
Pages : 130
Book Description
Publisher:
ISBN:
Category : Simulation methods
Languages : en
Pages : 130
Book Description
An Experimental Study in Three-dimensional Turbulent Boundary Layers on a Flat Plate with Parallel Flow
Author: Milton George Wille
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 218
Book Description
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 218
Book Description
An Experimental Investigation of Pressure Driven Three-dimensional Turbulent Boundary Layers
Author: Stanford University. Thermosciences Division
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 390
Book Description
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 390
Book Description
Experimental Study of a Three-dimensional Shear-driven Turbulent Boundary Layer with Streamwise Adverse Pressure Gradient
Author: David Michael Driver
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 268
Book Description
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 268
Book Description
Experimental Study of a Three-Dimensional Shear-Driven Turbulent Boundary Layer with Streamwise Adverse Pressure Gradient
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781723575372
Category :
Languages : en
Pages : 266
Book Description
The effects of a strong adverse pressure gradient on a three-dimensional turbulent boundary layer are studied in an axisymmetric spinning cylinder geometry. Velocity measurements made with a three-component laser Doppler velocimeter include all three mean flow components, all six Reynolds stress components, and all ten triple-product correlations. Reynolds stress diminishes as the flow becomes three-dimensional. Lower levels of shear stress were seen to persist under adverse pressure gradient conditions. This low level of stress was seen to roughly correlate with the magnitude of cross-flow (relative to free stream flow) for this experiment as well as most of the other experiments in the literature. Variations in pressure gradient do not appear to alter this correlation. For this reason, it is hypothesized that a three-dimensional boundary layer is more prone to separate than a two-dimensional boundary layer, although it could not be directly shown here. None of the computations performed with either a Prandtl mixing length, k-epsilon, or a Launder-Reece-Rodi full Reynolds-stress model were able to predict the reduction in Reynolds stress. Driver, David M. and Johnston, James P. Ames Research Center NASA-TM-102211, A-89104, NAS 1.15:102211, NONP-NASA-SUPPL-CD-ROM-93-159790 RTOP 505-60-11...
Publisher: Createspace Independent Publishing Platform
ISBN: 9781723575372
Category :
Languages : en
Pages : 266
Book Description
The effects of a strong adverse pressure gradient on a three-dimensional turbulent boundary layer are studied in an axisymmetric spinning cylinder geometry. Velocity measurements made with a three-component laser Doppler velocimeter include all three mean flow components, all six Reynolds stress components, and all ten triple-product correlations. Reynolds stress diminishes as the flow becomes three-dimensional. Lower levels of shear stress were seen to persist under adverse pressure gradient conditions. This low level of stress was seen to roughly correlate with the magnitude of cross-flow (relative to free stream flow) for this experiment as well as most of the other experiments in the literature. Variations in pressure gradient do not appear to alter this correlation. For this reason, it is hypothesized that a three-dimensional boundary layer is more prone to separate than a two-dimensional boundary layer, although it could not be directly shown here. None of the computations performed with either a Prandtl mixing length, k-epsilon, or a Launder-Reece-Rodi full Reynolds-stress model were able to predict the reduction in Reynolds stress. Driver, David M. and Johnston, James P. Ames Research Center NASA-TM-102211, A-89104, NAS 1.15:102211, NONP-NASA-SUPPL-CD-ROM-93-159790 RTOP 505-60-11...
An Experimental Investigation of a Three-dimensional Turbulent Boundary Layer
Author: Donald Ralph Zimmerman
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 348
Book Description
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 348
Book Description
An Experimental Investigation of a Two and a Three-Dimensional Low Speed Turbulent Boundary Layer
Author: A. E. Winkelmann
Publisher:
ISBN:
Category :
Languages : en
Pages : 191
Book Description
Experimental studies of a two and a three-dimensional low speed turbulent boundary layer were conducted on the side wall of the University of Maryland Boundary Layer Wind Tunnel. Preliminary studies in the two-dimensional boundary layer indicated that the flow was nonuniform on the 46 in. wide test wall. The nonuniform boundary layer is characterized by transverse variations in the wall shear stress and is primarily caused by nonuniformities in the inlet damping screens. Over the 15 in. span of a special transverse device, the local skin friction coefficient varied (at discrete locations) + or - 9% about a mean. Transverse variations in the flow velocity, yaw, pitch and turbulence intensity were also measured in the boundary layer at set distances above the wall. Measurements with a pitch probe revealed the presence of a vortex-like flow to exist above the edge of the boundary layer at two locations along the 15 in. traverse line.
Publisher:
ISBN:
Category :
Languages : en
Pages : 191
Book Description
Experimental studies of a two and a three-dimensional low speed turbulent boundary layer were conducted on the side wall of the University of Maryland Boundary Layer Wind Tunnel. Preliminary studies in the two-dimensional boundary layer indicated that the flow was nonuniform on the 46 in. wide test wall. The nonuniform boundary layer is characterized by transverse variations in the wall shear stress and is primarily caused by nonuniformities in the inlet damping screens. Over the 15 in. span of a special transverse device, the local skin friction coefficient varied (at discrete locations) + or - 9% about a mean. Transverse variations in the flow velocity, yaw, pitch and turbulence intensity were also measured in the boundary layer at set distances above the wall. Measurements with a pitch probe revealed the presence of a vortex-like flow to exist above the edge of the boundary layer at two locations along the 15 in. traverse line.
Near-Wall Investigation of Three-Dimensional Turbulent Boundary Layers
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 213
Book Description
This report documents the experimental study for four different three-dimensional turbulent flows. The investigation focuses on near wall measurements in these flows. Several experimental techniques are used in the studies; however, the bulk of the investigation focuses on a three-orthogonal-velocity-component fiber-optic laser Doppler anemometer (3D-LDA) system. The control volume of the 3D-LDA is on the order of 50 micro-meter in size, or a y+ distance of around 2.3 units (using average values of U? and? from the experiment). An auxiliary small boundary layer wind tunnel (auxiliary tunnel) and a low speed linear compressor cascade wind tunnel (cascade tunnel) are utilized in this study. One of four flow experiments is done in the auxiliary tunnel the other three are in the cascade tunnel. The first three-dimensional turbulent flow is a vortical flow created by two half-delta wing vortex generators. Near wall secondary flow features are found. The second flow is an investigation of the first quarter chord tip gap flow in the cascade tunnel. Strong three-dimensional phenomena are found. The third flow investigated is the inflow to the compressor cascade with the moving wall. The experiment records shear layer interaction between the upstream flow and moving wall. Finally the fourth flow investigated is the inflow to the compressor cascade with the moving wall with half-delta wing vortex generators attached. Phase-averaged data reveal asymmetrical vortex structures just downstream of thevortex generators. This is the first time any near wall data has been taken on any of these flows.
Publisher:
ISBN:
Category :
Languages : en
Pages : 213
Book Description
This report documents the experimental study for four different three-dimensional turbulent flows. The investigation focuses on near wall measurements in these flows. Several experimental techniques are used in the studies; however, the bulk of the investigation focuses on a three-orthogonal-velocity-component fiber-optic laser Doppler anemometer (3D-LDA) system. The control volume of the 3D-LDA is on the order of 50 micro-meter in size, or a y+ distance of around 2.3 units (using average values of U? and? from the experiment). An auxiliary small boundary layer wind tunnel (auxiliary tunnel) and a low speed linear compressor cascade wind tunnel (cascade tunnel) are utilized in this study. One of four flow experiments is done in the auxiliary tunnel the other three are in the cascade tunnel. The first three-dimensional turbulent flow is a vortical flow created by two half-delta wing vortex generators. Near wall secondary flow features are found. The second flow is an investigation of the first quarter chord tip gap flow in the cascade tunnel. Strong three-dimensional phenomena are found. The third flow investigated is the inflow to the compressor cascade with the moving wall. The experiment records shear layer interaction between the upstream flow and moving wall. Finally the fourth flow investigated is the inflow to the compressor cascade with the moving wall with half-delta wing vortex generators attached. Phase-averaged data reveal asymmetrical vortex structures just downstream of thevortex generators. This is the first time any near wall data has been taken on any of these flows.