scholarly journals Measurements of the Turbulent Boundary Layer in the Diffuser Behind an Axial-Compressor

1986 ◽  
Author(s):  
H. Pfeil ◽  
M. Göing
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Flow Direction ◽  
Three Dimensional ◽  
Great Influence ◽  
Axial Compressor ◽  
One Stage ◽  
Dimensional Effects ◽  
Diffuser Flow ◽  
Outlet Flow

The paper presents boundary layer measurements in a diffuser behind a one-stage axial-compressor for the case of nearly axial outlet flow-direction from the blades. According to the results, three-dimensional effects caused by the compressor-blading have a great influence on the character and development of the turbulent boundary layer and must be included in methods to predict the diffuser flow.

Measurements of the Turbulent Boundary Layer in the Diffuser Behind an Axial Compressor

1987 ◽  
Vol 109 (3) ◽  
pp. 405-412 ◽  
Author(s):  
H. Pfeil ◽  
M. Go¨ing
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Flow Direction ◽  
Three Dimensional ◽  
Great Influence ◽  
Axial Compressor ◽  
One Stage ◽  
Dimensional Effects ◽  
Diffuser Flow ◽  
Outlet Flow

This paper presents boundary layer measurements in a diffuser behind a one-stage axial compressor for the case of nearly axial outlet flow direction from the blades. According to the results, three-dimensional effects caused by the compressor blading have a great influence on the character and development of the turbulent boundary layer and must be included in methods to predict the diffuser flow.

Turbulent Boundary Layer and Flow Resistance on Plates Roughened by Wires

1976 ◽  
Vol 98 (4) ◽  
pp. 635-643 ◽  
Author(s):  
Y. Furuya ◽  
M. Miyata ◽  
H. Fujita
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Surface Resistance ◽  
Flow Resistance ◽  
Flow Direction ◽  
Roughness Element ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Secondary Currents ◽  
Pressure Drag

The flow resistance in a plate roughened by equally spaced wires at right angles to the flow direction was investigated experimentally by measuring the turbulent boundary layer developing along it. Measurements of pressure distribution around a roughness element revealed that the pressure drag accounts for a large portion of the surface resistance and remaining skin frictional part is almost equal to that of a smooth plate. Measurements were also made for plates having three-dimensional roughness. These plates were roughened by short wires in a staggered manner. In this case, the boundary layer was found to have a three-dimensional structure due to accompanying secondary currents.

Multi-Plane Characterization of the Turbulent Boundary Layer

2018 ◽  
Author(s):  
Kadeem Dennis ◽  
Kamran Siddiqui
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Turbulent Flow ◽  
Flow Direction ◽  
Fluid Velocity ◽  
Three Dimensional ◽  
Wall Region ◽  
Turbulent Structures ◽  
Turbulent Flow Structure

The boundary layers are known for their significance in several engineering systems. In particular, the inner region of the turbulent boundary layer has been shown to play a significant role in controlling the dynamics of turbulent structures that are responsible for the transport of mass, heat and momentum. While substantial work has been done in the past to characterize the structure of turbulent flow in this region, the characterization of the three-dimensional turbulent flow structure is limited. This study reports a multi-plane particle image velocimetry (PIV) approach to investigate three-dimensional dynamics of the turbulent boundary layer in the near-wall region. Planar PIV is used to capture two-dimensional fluid velocity fields in several planes with respect to the fluid flow direction. These results are used to describe three-dimensional turbulent events given by key quantities such as mean and turbulent velocities and turbulent kinetic energy.

An experimental study of the mechanism of intermittent separation of a turbulent boundary layer

1984 ◽  
Vol 143 ◽  
pp. 153-172 ◽  
Author(s):  
Qing-Ding Wei ◽  
Hiroshi Sato
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Flow Field ◽  
Large Scale ◽  
Flow Direction ◽  
Quantitative Description ◽  
Three Dimensional ◽  
Field Measurements ◽  
Separation Region ◽  
Average Technique

A wind-tunnel investigation was made of the mechanism of separation of a two-dimensional turbulent boundary layer on a convex wall. The flow field was observed visually by using a large number of smoke wires arranged in various ways. Statistical quantities were obtained by newly developed direction-sensitive hot-wire probes and flow-direction meters. Smoke pictures show localized backflow spots in the separation region. They occur intermittently, grow downstream, merge with each other and eventually cover the whole flow field. Measurements of instantaneous flow direction show that velocity fluctuations in the separation region are strongly three-dimensional. The backflow factor, which is defined as the fraction of time of occurrence of backflow, is used for the quantitative description of the separation region. The role of large-scale ordered motions in the turbulent separation was investigated by use of the conditional sample and average technique. It was confirmed that a localized backflow is initiated by a large-scale low-speed lump of fluid which travels downstream.

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