Convective Transport Phenomena on the Suction Surface of a Turbine Blade Including the Influence of Secondary Flows Near the Endwall

1992 ◽  
Vol 114 (4) ◽  
pp. 776-787 ◽  
Author(s):  
P. H. Chen ◽  
R. J. Goldstein
Keyword(s):  
Mass Transfer ◽  
Turbine Blade ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Convective Transport ◽  
Secondary Flows ◽  
Two Dimensional ◽  
Suction Surface ◽  
Dimensional Flow ◽  
Two Dimensional Flow

A naphthalene sublimation technique is employed to study the mass transfer distribution on the suction (convex) surface of a simulated turbine blade. Comparison with a heat transfer study shows good agreement in the general trends in the region of two-dimensional flow on the blade. Near the endwall, local connective coefficients on the suction surface are obtained at 4608 locations from two separate runs. The secondary flows in the passage significantly affect the mass transfer rate on the suction surface and their influence extends to a height of 75 percent of the chord length, from the endwall, in the trailing edge region. The mass transfer rate in the region near the endwall is extremely high due to small but intense vortices. Thus, a large variation in the mass transfer distribution occurs on the suction surface, from a mass transfer Stanton number of 0.0005 to a maximum of 0.01. In the two-dimensional flow region, the mass transfer distributions at two different Reynolds numbers are presented.

scholarly journals Convective Transport Phenomena on the Suction Surface of a Turbine Blade Including the Influence of Secondary Flows Near the Endwall

1991 ◽  
Author(s):  
P. H. Chen ◽  
R. J. Goldstein
Keyword(s):  
Mass Transfer ◽  
Turbine Blade ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Convective Transport ◽  
Secondary Flows ◽  
Two Dimensional ◽  
Suction Surface ◽  
Dimensional Flow ◽  
Two Dimensional Flow

A naphthalene sublimation technique is employed to study the mass transfer distribution on the suction (convex) surface of a simulated turbine blade. Comparison with a heat transfer study shows good agreement in the general trends in the region of two-dimensional flow on the blade. Near the endwall, local convective coefficients on the suction surface are obtained at 4608 locations from two separate runs. The secondary flows in the passage significantly affect the mass transfer rate on the suction surface and their influence extends to a height of 75% of the chord length, from the endwall, in the trailing edge region. The mass transfer rate in the region near the endwall is extremely high due to small but intense vortices. Thus, a large variation in the mass transfer distribution occurs on the suction surface, from a mass transfer Stanton number of 0.0005 to a maximum of 0.01. In the two-dimensional flow region, the mass transfer distributions at two different Reynolds number are presented.

Darryl E. Metzger Memorial Session Paper: The Influence of Secondary Flows Near the Endwall and Boundary Layer Disturbance on Convective Transport From a Turbine Blade

1995 ◽  
Vol 117 (4) ◽  
pp. 657-665 ◽  
Author(s):  
R. J. Goldstein ◽  
H. P. Wang ◽  
M. Y. Jabbari
Keyword(s):  
Mass Transfer ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Leading Edge ◽  
Flow Region ◽  
Suction Side ◽  
Convective Transport ◽  
Pressure Side ◽  
Suction Surface ◽  
Passage Vortex

A naphthalene sublimation technique is used to investigate convective transport from a simulated turbine blade in a stationary linear cascade. In some of the tests undertaken, a trip wire is stretched along the span of the blade near the leading edge. The disturbance produced by tripping the boundary layers on the blade near the leading edge causes early boundary layer transition, creates high mass transfer rate on the pressure side and in the laminar flow region on the suction side, but lowers the transfer rate in the turbulent flow region on the suction side. Comparison is made with other heat and mass transfer studies in the two-dimensional region far from the endwall and good agreement is found. Near the endwall, flow visualization indicates a strong secondary flow pattern. The impact of vortices initiated near the endwall on the laminar–turbulent transition extends three-dimensional effects to about 0.8 chord lengths on the suction side and to about 0.2 chord lengths on the pressure side away from the endwall. The effect of the passage vortex and the new vortex induced by the passage vortex on mass transfer is clearly seen and can be traced along the suction surface of the blade. Close to the endwall the highest mass transfer rate on the suction surface is not found near the leading edge. It occurs at about 27 percent of the curvilinear distance from the stagnation line to the trailing edge where a strong main flow and the secondary passage flow from the pressure side of the adjacent blade interact. The influences of some small but very intense corner vortices and the passage vortex on mass transfer are also observed on both surfaces of the blade.

scholarly journals The Influence of Secondary Flows Near the Endwall and Boundary Layer Disturbance on Convective Transport From a Turbine Blade

1994 ◽  
Author(s):  
R. J. Goldstein ◽  
H. P. Wang ◽  
M. Y. Jabbari
Keyword(s):  
Mass Transfer ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Leading Edge ◽  
Flow Region ◽  
Suction Side ◽  
Convective Transport ◽  
Pressure Side ◽  
Suction Surface ◽  
Passage Vortex

A naphthalene sublimation technique is used to investigate convective transport from a simulated turbine blade in a stationary linear cascade. In some of the tests undertaken a trip wire is stretched along the span of the blade near the leading edge. The disturbance produced by tripping the boundary layers on the blade near the leading edge causes early boundary layer transition, creates high mass transfer rate on the pressure side and in the laminar flow region on the suction side, but lowers the transfer rate in the turbulent flow region on the suction side. Comparison is made with other heat and mass transfer studies in the two dimensional region far from the endwall and good agreement is found. Near the endwall, flow visualization indicates a strong secondary flow pattern. The impact of vortices initiated near the endwall on the laminar-turbulent transition extends three dimensional effects to about 0.8 chord lengths on the suction side and to about 0.2 chord lengths on the pressure side away from the endwall. The effect of the passage vortex and the new vortex induced by the passage vortex on mass transfer is clearly seen and can be traced along the suction surface of the blade. Close to the endwall the highest mass transfer rate on the suction surface is not found near the leading edge. It occurs at about 27% of the curvilinear distance from the stagnation line to the trailing edge where a strong main flow and the secondary passage flow from the pressure side of the adjacent blade interact. The influences of some small but very intense corner vortices and the passage vortex on mass transfer are also observed on both surfaces of the blade.

The Effect of a Wall Boundary Layer on Local Mass Transfer From a Cylinder in Crossflow

1984 ◽  
Vol 106 (2) ◽  
pp. 260-267 ◽  
Author(s):  
R. J. Goldstein ◽  
J. Karni
Keyword(s):  
Boundary Layer ◽  
Mass Transfer ◽  
Three Dimensional ◽  
Secondary Flows ◽  
Two Dimensional ◽  
Tunnel Wall ◽  
Wall Boundary Layer ◽  
Naphthalene Sublimation Technique ◽  
Displacement Thickness ◽  
Two Dimensional Flow

A naphthalene sublimation technique is used to determine the circumferential and longitudinal variations of mass transfer from a smooth circular cylinder in a crossflow of air. The effect of the three-dimensional secondary flows near the wall-attached ends of a cylinder is discussed. For a cylinder Reynolds number of 19000, local enhancement of the mass transfer over values in the center of the tunnel are observed up to a distance of 3.5 cylinder diameters from the tunnel wall. In a narrow span extending from the tunnel wall to about 0.066 cylinder diameters above it (about 0.75 of the mainstream boundary layer displacement thickness), increases of 90 to 700 percent over the two-dimensional flow mass transfer are measured on the front portion of the cylinder. Farther from the wall, local increases of up to 38 percent over the two-dimensional values are measured. In this region, increases of mass transfer in the rear portion of the cylinder, downstream of separation, are, in general, larger and cover a greater span than the increases in the front portion of the cylinder.

Measurement of NAPL–water interfacial areas and mass transfer rates in two-dimensional flow cell

2016 ◽  
Vol 74 (9) ◽  
pp. 2145-2151 ◽  
Author(s):  
Muzi Li ◽  
Yuanzheng Zhai ◽  
Li Wan
Keyword(s):  
Mass Transfer ◽  
Interfacial Area ◽  
Chemical Oxidation ◽  
Flow Cell ◽  
Two Dimensional ◽  
Transfer Rates ◽  
Dimensional Flow ◽  
Interfacial Areas ◽  
Two Dimensional Flow

The nonaqueous-phase liquid (NAPL)–water interfacial area and the mass transfer rate across the NAPL and water interface are often key factors in in situ groundwater pollution treatment. In this study, the NAPL–water interfacial area and residual NAPL saturation were measured using interfacial and partitioning tracer tests in a two-dimensional flow cell. The results were compared with previous column and field experiment results. In addition, the mass transfer rates at various NAPL–water interfacial areas were investigated. Fe2+-activated persulfate was used for in situ chemical oxidation remediation to remove NAPL gradually. The results showed that the reduction of NAPL–water interfacial areas as well as NAPL saturation by chemical oxidation caused a linear decrease in the interphase mass transfer rates (R2 = 0.97), revealing the relationship between mass transfer rates and interfacial areas in a two-dimensional system. The NAPL oxidation rates decreased with the reduction of interfacial areas, owing to the control of NAPL mass transfer into the aqueous phase.

scholarly journals The Effect of Interfacial Turbulence upon Mass Transfer Rate in Two Dimensional Test Cell

1973 ◽  
Vol 37 (5) ◽  
pp. 504-509,a1
Author(s):  
Yasuo Nakaike ◽  
Tsunehiko Sato ◽  
Tatsuo Go
Keyword(s):  
Mass Transfer ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Test Cell ◽  
Two Dimensional

scholarly journals Local Mass and Heat Transfer on a Turbine Blade Tip

2003 ◽  
Vol 9 (2) ◽  
pp. 81-95 ◽  
Author(s):  
P. Jin ◽  
R. J. Goldstein
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Turbine Blade ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Tip Clearance ◽  
Transfer Rates ◽  
Average Mass ◽  
Blade Tip ◽  
Mass And Heat Transfer

Local mass and heat transfer measurements on a simulated high-pressure turbine blade-tip surface are conducted in a linear cascade with a nonmoving tip endwall, using a naphthalene sublimation technique. The effects of tip clearance (0.86–6.90% of chord) are investigated at various exit Reynolds numbers (4–7 ×105) and turbulence intensities (0.2 and 12.0%).The mass transfer on the tip surface is significant along its pressure edge at the smallest tip clearance. At the two largest tip clearances, the separation bubble on the tip surface can cover the whole width of the tip on the second half of the tip surface. The average mass-transfer rate is highest at a tip clearance of 1.72% of chord. The average mass-transfer rate on the tip surface is four and six times as high as on the suction and the pressure surface, respectively. A high mainstream turbulence level of 12.0% reduces average mass-transfer rates on the tip surface, while the higher mainstream Reynolds number generates higher local and average mass-transfer rates on the tip surface.

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