Author: Baafour Nyantekyi-Kwakye
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
An experimental study was designed to investigate the effect of different parameters on the development and structure of turbulent 3D offset jets. The present investigation considered the effects of offset height ratio, expansion ratio, surface roughness and rib placement on the flow dynamics of a turbulent 3D offset jet. The velocity measurements were performed using an acoustic Doppler velocimetry (ADV) and particle image velocimetry (PIV). Measurements were conducted within the symmetry and lateral planes. For the PIV technique, the measurements in the symmetry and lateral planes were conducted over a streamwise range of 0 ≤ x/bo ≤ 80 and 12 ≤ x/bo ≤ 60, respectively (where bo is the nozzle height). Likewise, velocity measurements using the ADV technique were conducted over a range of 4 ≤ x/bo ≤ 45 in both the symmetry and lateral planes. The velocity measurements were analyzed using both one-point and multi-point statistics. The one-point statistics included profiles of the mean velocities, Reynolds stresses and some of the budget terms in the turbulent kinetic energy transport equation. The quadrant analysis technique was used to investigate the dominant events that contribute towards the Reynolds shear stress. The two-point correlation analysis was used to investigate how the turbulence quantities are correlated. Information obtained from the two-point correlation analysis was also used to investigate the inclination of vortical structures within the inner and outer shear layers of the 3D offset jet. The direction of the positive mean shear gradient played an active role in the inclination of these vortical structures within the inner and outer shear layers. The reattachment process resulted in the breakdown of these structures within the developing region. Similarly, various length scales were estimated from these structures. The proper orthogonal decomposition was used to examine the distribution of the turbulent kinetic energy within the offset jet flow. Also, the dynamic role of the large scale structures towards the turbulent intensities, turbulent kinetic energy and Reynolds shear stress was investigated.
Experimental Investigation on the Flow Characteristics of Three-dimensional Turbulent Offset Jets
Author: Baafour Nyantekyi-Kwakye
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
An experimental study was designed to investigate the effect of different parameters on the development and structure of turbulent 3D offset jets. The present investigation considered the effects of offset height ratio, expansion ratio, surface roughness and rib placement on the flow dynamics of a turbulent 3D offset jet. The velocity measurements were performed using an acoustic Doppler velocimetry (ADV) and particle image velocimetry (PIV). Measurements were conducted within the symmetry and lateral planes. For the PIV technique, the measurements in the symmetry and lateral planes were conducted over a streamwise range of 0 ≤ x/bo ≤ 80 and 12 ≤ x/bo ≤ 60, respectively (where bo is the nozzle height). Likewise, velocity measurements using the ADV technique were conducted over a range of 4 ≤ x/bo ≤ 45 in both the symmetry and lateral planes. The velocity measurements were analyzed using both one-point and multi-point statistics. The one-point statistics included profiles of the mean velocities, Reynolds stresses and some of the budget terms in the turbulent kinetic energy transport equation. The quadrant analysis technique was used to investigate the dominant events that contribute towards the Reynolds shear stress. The two-point correlation analysis was used to investigate how the turbulence quantities are correlated. Information obtained from the two-point correlation analysis was also used to investigate the inclination of vortical structures within the inner and outer shear layers of the 3D offset jet. The direction of the positive mean shear gradient played an active role in the inclination of these vortical structures within the inner and outer shear layers. The reattachment process resulted in the breakdown of these structures within the developing region. Similarly, various length scales were estimated from these structures. The proper orthogonal decomposition was used to examine the distribution of the turbulent kinetic energy within the offset jet flow. Also, the dynamic role of the large scale structures towards the turbulent intensities, turbulent kinetic energy and Reynolds shear stress was investigated.
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
An experimental study was designed to investigate the effect of different parameters on the development and structure of turbulent 3D offset jets. The present investigation considered the effects of offset height ratio, expansion ratio, surface roughness and rib placement on the flow dynamics of a turbulent 3D offset jet. The velocity measurements were performed using an acoustic Doppler velocimetry (ADV) and particle image velocimetry (PIV). Measurements were conducted within the symmetry and lateral planes. For the PIV technique, the measurements in the symmetry and lateral planes were conducted over a streamwise range of 0 ≤ x/bo ≤ 80 and 12 ≤ x/bo ≤ 60, respectively (where bo is the nozzle height). Likewise, velocity measurements using the ADV technique were conducted over a range of 4 ≤ x/bo ≤ 45 in both the symmetry and lateral planes. The velocity measurements were analyzed using both one-point and multi-point statistics. The one-point statistics included profiles of the mean velocities, Reynolds stresses and some of the budget terms in the turbulent kinetic energy transport equation. The quadrant analysis technique was used to investigate the dominant events that contribute towards the Reynolds shear stress. The two-point correlation analysis was used to investigate how the turbulence quantities are correlated. Information obtained from the two-point correlation analysis was also used to investigate the inclination of vortical structures within the inner and outer shear layers of the 3D offset jet. The direction of the positive mean shear gradient played an active role in the inclination of these vortical structures within the inner and outer shear layers. The reattachment process resulted in the breakdown of these structures within the developing region. Similarly, various length scales were estimated from these structures. The proper orthogonal decomposition was used to examine the distribution of the turbulent kinetic energy within the offset jet flow. Also, the dynamic role of the large scale structures towards the turbulent intensities, turbulent kinetic energy and Reynolds shear stress was investigated.
An Experimental Investigation of a Turbulent, Incompressible, Three-dimensional Wall Jet
Author: Hermann Viets
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 40
Book Description
This paper presents an experimental investigation of the bulk properties of a turbulent, three-dimensional, incompressible air wall jet issuing into a quiescent air ambient from a rectangular orifice parallel to and at the surface of a flat plate. Results of this study indicate the characteristic features of such a dissipative flow. The behavior of a three-dimensional flow field of this nature has associated with it three distinct regions in the axis velocity decay with an approach to the flow field of a radial wall jet far downstream of the jet exit and on the centerline of the flow. Spreading rates in the various cross planes display a dependence upon the aforementioned characteristic regions. (Author).
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 40
Book Description
This paper presents an experimental investigation of the bulk properties of a turbulent, three-dimensional, incompressible air wall jet issuing into a quiescent air ambient from a rectangular orifice parallel to and at the surface of a flat plate. Results of this study indicate the characteristic features of such a dissipative flow. The behavior of a three-dimensional flow field of this nature has associated with it three distinct regions in the axis velocity decay with an approach to the flow field of a radial wall jet far downstream of the jet exit and on the centerline of the flow. Spreading rates in the various cross planes display a dependence upon the aforementioned characteristic regions. (Author).
Experimental Study of Three-dimensional Turbulent Offset Jets and Wall Jets
Author: Martin Agelin-Chaab
Publisher:
ISBN:
Category :
Languages : en
Pages : 368
Book Description
Turbulence kinetic energy -- particle image velocimetry -- proper orthogonal decomposition -- two-point velocity correlations -- triple velocity products -- harpin vortex -- turbulenc production.
Publisher:
ISBN:
Category :
Languages : en
Pages : 368
Book Description
Turbulence kinetic energy -- particle image velocimetry -- proper orthogonal decomposition -- two-point velocity correlations -- triple velocity products -- harpin vortex -- turbulenc production.
An Experimental Investigation of the Turbulent and Mean Flow Properties of a Plane Two-dimensional Turbulent Wall Jet
Experimental Flow Characteristics of a Single Turbulent Jet Impinging on a Flat Plate
An Experimental Investigation of Three-dimensional Free Mixing of Incompressible, Turbulent, Free Jets
Author: Nicholas Trentacoste
Publisher:
ISBN:
Category : Jets
Languages : en
Pages : 72
Book Description
An experimental investigation of the bulk properties of turbulent, three-dimensional, incompressible, air jets issuing into a quiescent air ambient is presented. The jet orifices utilized included rectangular, elliptical, axisymmetric and triangular geometries. Experimental results of pertinent mean flow properties such as axis velocity decay, half-width growth, etc., are reported. The flow fields of such jets are found to be characterized by three distinct regions in the axis velocity decay. The results obtained lead to the conclusion that low-speed jets which originate from non-axisymmetric orifices decay to axisymmetry far downstream of the jet exit. (Author).
Publisher:
ISBN:
Category : Jets
Languages : en
Pages : 72
Book Description
An experimental investigation of the bulk properties of turbulent, three-dimensional, incompressible, air jets issuing into a quiescent air ambient is presented. The jet orifices utilized included rectangular, elliptical, axisymmetric and triangular geometries. Experimental results of pertinent mean flow properties such as axis velocity decay, half-width growth, etc., are reported. The flow fields of such jets are found to be characterized by three distinct regions in the axis velocity decay. The results obtained lead to the conclusion that low-speed jets which originate from non-axisymmetric orifices decay to axisymmetry far downstream of the jet exit. (Author).
An Experimental Investigation of a Three Dimensional Wall Jet
Author: George Dominic Catalano
Publisher:
ISBN:
Category : Jets
Languages : en
Pages : 390
Book Description
Publisher:
ISBN:
Category : Jets
Languages : en
Pages : 390
Book Description
Investigation of Features of Flow of Three-Dimensional Turbulent Wall Jets with and Without Pressure Gradient
Author: John R. Weske
Publisher:
ISBN:
Category :
Languages : en
Pages : 24
Book Description
The characteristics of 3-dimensional wall jets are strongly influenced by secondary motion particularly in the region close to the nozzle. There is evidence suggesting that jets from narrow and tall nozzles will spread a wall jet more broadly over a wall than low and broad nozzles. Three-dimensional wall jets with pressure gradients, in the region close to the nozzle are subject to the same effects of secondary motions as are wall jets without pressure gradients, while in their later course they may acquire the characteristics of turbulent flow in ducts. Theoretical investigation of the action of Reynolds stresses serves to clarify the nature of secondary motions and to show the reason for contrasting characteristics of secondary flow in jets and in ducts as well as the fading out of secondary motion with increasing jet diffusion. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 24
Book Description
The characteristics of 3-dimensional wall jets are strongly influenced by secondary motion particularly in the region close to the nozzle. There is evidence suggesting that jets from narrow and tall nozzles will spread a wall jet more broadly over a wall than low and broad nozzles. Three-dimensional wall jets with pressure gradients, in the region close to the nozzle are subject to the same effects of secondary motions as are wall jets without pressure gradients, while in their later course they may acquire the characteristics of turbulent flow in ducts. Theoretical investigation of the action of Reynolds stresses serves to clarify the nature of secondary motions and to show the reason for contrasting characteristics of secondary flow in jets and in ducts as well as the fading out of secondary motion with increasing jet diffusion. (Author).
Theoretical and experimental investigation of three dimensional turbulent missing in jets and ducts
Characteristics of Three-dimensional Turbulent Jets
Author: Choudary Rama Krishna Bobba
Publisher:
ISBN:
Category :
Languages : en
Pages : 250
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 250
Book Description