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Masahiro Inoue  One of the best experts on this subject based on the ideXlab platform.

Behavior of threedimensional boundary layers in a Radial inflow turbine scroll
Journal of Turbomachinery, 1994CoAuthors: Kazuo Hara, Masato Furukawa, Masahiro InoueAbstract:A detailed experimental investigation was carried out to examine the threedimensional boundary layer characteristics in a Radial inflow turbine scroll. Some basic flow phenomena and growth of secondary flow were also investigated. In the inlet region of the scroll, the incoming boundary layer begins to have a skewed nature, namely the Radially in ward secondary flow caused by the Radial Pressure Gradient. From the inlet region to one third of the scroll circumference, the secondary flow grows so strongly that most of the lowmomentum fluid in the incoming boundary layer is transported to the nozzle region

Behavior of threedimensional boundary layers in a Radial inflow turbine scroll
Journal of Turbomachinery, 1994CoAuthors: Kazuo Hara, Masato Furukawa, Masahiro InoueAbstract:A detailed experimental investigation was carried out to examine the threedimensional boundary layer characteristics in a Radial inflow turbine scroll. Some basic flow phenomena and growth of secondary flow were also investigated. In the inlet region of the scroll, the incoming boundary layer begins to have a skewed nature, namely the Radially inward secondary flow caused by the Radial Pressure Gradient. From the inlet region to one third of the scroll circumference, the secondary flow grows so strongly that most of the lowmomentum fluid in the incoming boundary layer is transported to the nozzle region. The succeeding elimination of the lowmomentum fluid in the boundary layer suppresses growth of the boundary layer farther downstream, where the boundary layer shows a similar velocity profile. The distributions of the boundary layer properties in the scroll correspond well to those of the flow properties at the nozzle. The behavior of the boundary layer in the scroll is found to affect the circumferential nonuniformity of the nozzle flow field.

Boundary Layer and Formation of Peripheral Nonuniformity in a Turbine Scroll
Transactions of the Japan Society of Mechanical Engineers Series B, 1994CoAuthors: Kazuo Hara, Masato Furukawa, Masahiro InoueAbstract:A detailed experimental investigation was carried out to examine the threedimensional boundary layer characteristics in a Radial inflow turbine scroll. Some basic flow phenomena and growth of secondary flow were also investigated. In the inlet region of the scroll, the incoming boundary layer begins to assume a skewed nature, namely the Radially inward secondary flow caused by the Radial Pressure Gradient. From the inlet region to onethird of the scroll circumference, the secondary flow increases largely that most of the lowmomentum fluid in the incoming boundary layer is transported to the nozzle region. The succeeding elimination of the lowmomentum fluid in the boundary layer suppresses growth of the boundary layer further downstream, where the boundary layer shows a selfsimilar velocity profile. The distributions of the boundary layer properties in the scroll correspond well to those of the flow properties at the nozzle. The behavior of the boundary layer in the scroll is found to affect the circumferential nonuniformity of the nozzle flow field.

Behavior of ThreeDimensional Boundary Layers in a Radial Inflow Turbine Scroll
Volume 1: Aircraft Engine; Marine; Turbomachinery; Microturbines and Small Turbomachinery, 1993CoAuthors: Kazuo Hara, Masato Furukawa, Masahiro InoueAbstract:A detailed experimental investigation was carried out to examine the threedimensional boundary layer characteristics in a Radial inflow turbine scroll. Some basic flow phenomena and growth of secondary flow were also investigated. In the inlet region of the scroll, the incoming boundary layer begins to have the skewed nature, namely the Radially inward secondary flow caused by the Radial Pressure Gradient. From the inlet region to the one third of the scroll circumference, the secondary flow grows so strongly that the most of the low momentum fluid in the incoming boundary layer are transported to the nozzle region. The succeeding elimination of the low momentum fluid in the boundary layer suppresses growth of the boundary layer further downstream, where the boundary layer shows a similarity of velocity profile. The distributions of the boundary layer properties in the scroll correspond well to those of the flow properties at the nozzle. The behavior of the boundary layer in the scroll is found to affect the circumferential nonuniformity of the nozzle flow field.
Kazuo Hara  One of the best experts on this subject based on the ideXlab platform.

Behavior of threedimensional boundary layers in a Radial inflow turbine scroll
Journal of Turbomachinery, 1994CoAuthors: Kazuo Hara, Masato Furukawa, Masahiro InoueAbstract:A detailed experimental investigation was carried out to examine the threedimensional boundary layer characteristics in a Radial inflow turbine scroll. Some basic flow phenomena and growth of secondary flow were also investigated. In the inlet region of the scroll, the incoming boundary layer begins to have a skewed nature, namely the Radially in ward secondary flow caused by the Radial Pressure Gradient. From the inlet region to one third of the scroll circumference, the secondary flow grows so strongly that most of the lowmomentum fluid in the incoming boundary layer is transported to the nozzle region

Behavior of threedimensional boundary layers in a Radial inflow turbine scroll
Journal of Turbomachinery, 1994CoAuthors: Kazuo Hara, Masato Furukawa, Masahiro InoueAbstract:A detailed experimental investigation was carried out to examine the threedimensional boundary layer characteristics in a Radial inflow turbine scroll. Some basic flow phenomena and growth of secondary flow were also investigated. In the inlet region of the scroll, the incoming boundary layer begins to have a skewed nature, namely the Radially inward secondary flow caused by the Radial Pressure Gradient. From the inlet region to one third of the scroll circumference, the secondary flow grows so strongly that most of the lowmomentum fluid in the incoming boundary layer is transported to the nozzle region. The succeeding elimination of the lowmomentum fluid in the boundary layer suppresses growth of the boundary layer farther downstream, where the boundary layer shows a similar velocity profile. The distributions of the boundary layer properties in the scroll correspond well to those of the flow properties at the nozzle. The behavior of the boundary layer in the scroll is found to affect the circumferential nonuniformity of the nozzle flow field.

Boundary Layer and Formation of Peripheral Nonuniformity in a Turbine Scroll
Transactions of the Japan Society of Mechanical Engineers Series B, 1994CoAuthors: Kazuo Hara, Masato Furukawa, Masahiro InoueAbstract:A detailed experimental investigation was carried out to examine the threedimensional boundary layer characteristics in a Radial inflow turbine scroll. Some basic flow phenomena and growth of secondary flow were also investigated. In the inlet region of the scroll, the incoming boundary layer begins to assume a skewed nature, namely the Radially inward secondary flow caused by the Radial Pressure Gradient. From the inlet region to onethird of the scroll circumference, the secondary flow increases largely that most of the lowmomentum fluid in the incoming boundary layer is transported to the nozzle region. The succeeding elimination of the lowmomentum fluid in the boundary layer suppresses growth of the boundary layer further downstream, where the boundary layer shows a selfsimilar velocity profile. The distributions of the boundary layer properties in the scroll correspond well to those of the flow properties at the nozzle. The behavior of the boundary layer in the scroll is found to affect the circumferential nonuniformity of the nozzle flow field.

Behavior of ThreeDimensional Boundary Layers in a Radial Inflow Turbine Scroll
Volume 1: Aircraft Engine; Marine; Turbomachinery; Microturbines and Small Turbomachinery, 1993CoAuthors: Kazuo Hara, Masato Furukawa, Masahiro InoueAbstract:A detailed experimental investigation was carried out to examine the threedimensional boundary layer characteristics in a Radial inflow turbine scroll. Some basic flow phenomena and growth of secondary flow were also investigated. In the inlet region of the scroll, the incoming boundary layer begins to have the skewed nature, namely the Radially inward secondary flow caused by the Radial Pressure Gradient. From the inlet region to the one third of the scroll circumference, the secondary flow grows so strongly that the most of the low momentum fluid in the incoming boundary layer are transported to the nozzle region. The succeeding elimination of the low momentum fluid in the boundary layer suppresses growth of the boundary layer further downstream, where the boundary layer shows a similarity of velocity profile. The distributions of the boundary layer properties in the scroll correspond well to those of the flow properties at the nozzle. The behavior of the boundary layer in the scroll is found to affect the circumferential nonuniformity of the nozzle flow field.
T T Lim  One of the best experts on this subject based on the ideXlab platform.

on the relation between centrifugal force and Radial Pressure Gradient in flow inside curved and s shaped ducts
Physics of Fluids, 2008CoAuthors: S C Luo, T T LimAbstract:Swirl flow in a curved duct and Sduct is governed by a centrifugal force and Radial Pressure Gradient force between the sidewalls. In the present work, we introduce a dimensionless parameter that relates the ratio of these two forces and the duct’s centerline distance and show how the parameter is related to other more familiar dimensionless terms such as the Pressure coefficient, Reynolds number, and Dean number. By using published data as well as our own measurements, it is shown that the data collapse reasonably well on a curve when the proposed parameter is plotted against dimensionless distance along the duct. The existence of collapsed curves for ducts of different curvature ratios indicates that the proposed parameter can be used to characterize the flow, although some scatter in the data exists, due to the presence of flow separation and streamwise vortices along the wall of the curved ducts. An attempt to suppress flow separation by using vortex generators in the Sduct leads to some improvement in the collapsed curve at the first bend of the duct. The results reported here are mainly focused on square and circular constant crosssectioned 90° curved ducts and Sshaped ducts of different curvature ratios.
Masato Furukawa  One of the best experts on this subject based on the ideXlab platform.

Behavior of threedimensional boundary layers in a Radial inflow turbine scroll
Journal of Turbomachinery, 1994CoAuthors: Kazuo Hara, Masato Furukawa, Masahiro InoueAbstract:A detailed experimental investigation was carried out to examine the threedimensional boundary layer characteristics in a Radial inflow turbine scroll. Some basic flow phenomena and growth of secondary flow were also investigated. In the inlet region of the scroll, the incoming boundary layer begins to have a skewed nature, namely the Radially in ward secondary flow caused by the Radial Pressure Gradient. From the inlet region to one third of the scroll circumference, the secondary flow grows so strongly that most of the lowmomentum fluid in the incoming boundary layer is transported to the nozzle region

Behavior of threedimensional boundary layers in a Radial inflow turbine scroll
Journal of Turbomachinery, 1994CoAuthors: Kazuo Hara, Masato Furukawa, Masahiro InoueAbstract:A detailed experimental investigation was carried out to examine the threedimensional boundary layer characteristics in a Radial inflow turbine scroll. Some basic flow phenomena and growth of secondary flow were also investigated. In the inlet region of the scroll, the incoming boundary layer begins to have a skewed nature, namely the Radially inward secondary flow caused by the Radial Pressure Gradient. From the inlet region to one third of the scroll circumference, the secondary flow grows so strongly that most of the lowmomentum fluid in the incoming boundary layer is transported to the nozzle region. The succeeding elimination of the lowmomentum fluid in the boundary layer suppresses growth of the boundary layer farther downstream, where the boundary layer shows a similar velocity profile. The distributions of the boundary layer properties in the scroll correspond well to those of the flow properties at the nozzle. The behavior of the boundary layer in the scroll is found to affect the circumferential nonuniformity of the nozzle flow field.

Boundary Layer and Formation of Peripheral Nonuniformity in a Turbine Scroll
Transactions of the Japan Society of Mechanical Engineers Series B, 1994CoAuthors: Kazuo Hara, Masato Furukawa, Masahiro InoueAbstract:A detailed experimental investigation was carried out to examine the threedimensional boundary layer characteristics in a Radial inflow turbine scroll. Some basic flow phenomena and growth of secondary flow were also investigated. In the inlet region of the scroll, the incoming boundary layer begins to assume a skewed nature, namely the Radially inward secondary flow caused by the Radial Pressure Gradient. From the inlet region to onethird of the scroll circumference, the secondary flow increases largely that most of the lowmomentum fluid in the incoming boundary layer is transported to the nozzle region. The succeeding elimination of the lowmomentum fluid in the boundary layer suppresses growth of the boundary layer further downstream, where the boundary layer shows a selfsimilar velocity profile. The distributions of the boundary layer properties in the scroll correspond well to those of the flow properties at the nozzle. The behavior of the boundary layer in the scroll is found to affect the circumferential nonuniformity of the nozzle flow field.

Behavior of ThreeDimensional Boundary Layers in a Radial Inflow Turbine Scroll
Volume 1: Aircraft Engine; Marine; Turbomachinery; Microturbines and Small Turbomachinery, 1993CoAuthors: Kazuo Hara, Masato Furukawa, Masahiro InoueAbstract:A detailed experimental investigation was carried out to examine the threedimensional boundary layer characteristics in a Radial inflow turbine scroll. Some basic flow phenomena and growth of secondary flow were also investigated. In the inlet region of the scroll, the incoming boundary layer begins to have the skewed nature, namely the Radially inward secondary flow caused by the Radial Pressure Gradient. From the inlet region to the one third of the scroll circumference, the secondary flow grows so strongly that the most of the low momentum fluid in the incoming boundary layer are transported to the nozzle region. The succeeding elimination of the low momentum fluid in the boundary layer suppresses growth of the boundary layer further downstream, where the boundary layer shows a similarity of velocity profile. The distributions of the boundary layer properties in the scroll correspond well to those of the flow properties at the nozzle. The behavior of the boundary layer in the scroll is found to affect the circumferential nonuniformity of the nozzle flow field.
Olivier Métais  One of the best experts on this subject based on the ideXlab platform.

Large eddy simulations in curved square ducts: variation of the curvature radius
Journal of Turbulence, 2007CoAuthors: Cécile Münch, Olivier MétaisAbstract:We present largeeddy simulations of the turbulent compressible flow at a low Mach number in curved ducts. The aim is to investigate the influence of the curvature radius R c on the flow. Three simulations are carried out at R c = 3.5 D h , 6.5 D h and 10.5 D h (D h hydraulic diameter). We first validate our computations by comparison with the incompressible experiments performed by Chang et al. (1983, Turbulent flow in a strongly curved Ubend and downstream tangent of square crosssections. Physicochemical Hydrodynamics, 4(3), 243–269). We observe that the decrease of the curvature radius is accompanied by a strong intensification of the secondary transverse flows : a rise of 100% of the maximum of their intensity is obtained between the smaller and the higher values of R c . We show that the secondary flows strength is directly related to the Radial Pressure Gradient intensity. We observe a significant modification of the nearwall laws in the vicinity of each curved walls in correlation with the favo...

Large eddy simulations in curved square ducts: Variation of the curvature radius
Journal of Turbulence, 2007CoAuthors: Cécile Münch, Olivier MétaisAbstract:We present largeeddy simulations of the turbulent compressible flow at a low Mach number in curved ducts. The aim is to investigate the influence of the curvature radius R c on the flow. Three simulations are carried out at R c = 3.5 D h , 6.5 D h and 10.5 D h (D h hydraulic diameter). We first validate our computations by comparison with the incompressible experiments performed by Chang et al. (1983, Turbulent flow in a strongly curved Ubend and downstream tangent of square crosssections. Physicochemical Hydrodynamics, 4(3), 243–269). We observe that the decrease of the curvature radius is accompanied by a strong intensification of the secondary transverse flows : a rise of 100% of the maximum of their intensity is obtained between the smaller and the higher values of R c . We show that the secondary flows strength is directly related to the Radial Pressure Gradient intensity. We observe a significant modification of the nearwall laws in the vicinity of each curved walls in correlation with the favourable or the adverse streamwise Pressure Gradient depending on the nature of the curvature. The influence of R c on the coherent vortices is also estimated.

Large Eddy Simulation of the turbulent flow in heated curved ducts: influence of the Reynolds number
2005CoAuthors: Cécile Münch, Olivier MétaisAbstract:LargeEddy Simulations (LES) of the turbulent compressible flow within heated curved ducts of square cross section are presented. The aim here is to predict the threedimensional structures which develop inside cooling channels of rocket engines and study their effect on heat transfer rates. In this work, we focus on the influence of the Reynolds number on these structures and thus on the heat transfer characteristics. We first consider non heated curved ducts for two Reynolds numbers : 6000 and 12000. We observe that the the Ekman vortices corresponding to the secondary flow created by the Radial Pressure Gradient become larger in size at high Reynolds number. The Görtler vortices appearing on the concave wall, due to the centrifugal instability, are conversely smaller and more numerous. We then present simulations with heat: a constant heat flux is imposed on the convex wall of the curved duct. The Ekman vortices are found to be associated with an important transverse temperature Gradient on the heated wall. This Gradient intensifies when the Reynolds number is increased.

Large Eddy Simulations of Turbulent Flow in Curved and SShape Ducts
Direct and LargeEddy Simulation V, 2004CoAuthors: Cécile Münch, Jerome Hebrard, Olivier MétaisAbstract:We present LargeEddy Simulations (LES) of the turbulent compressible flow in a curved and an Sshape duct of square cross section. The aim is to predict the threedimensional structures which develop inside the cooling channels of heat exchangers and which dominate the heat transfer with the heated wall. We first consider a curved duct with one curvature only and then an Sshape duct with two opposite curvatures. We observe the formation of Gortler vortices which are moved close to the convex wall by the Radial Pressure Gradient between the two curved faces. These are associated with a secondary flow of over 20% of the streamwise velocity. We determine the influence of wall heating and consecutively consider the case of concave wall heating and of convex wall heating. Due to the secondary flow associated with the Gortler vortices, we observe an enhancement of the heat flux in the first case and an inhibition in the second case.