Flow Structure Transition inside Contra-Rotating Disk Cavity

Chen, Shu Xian; Shi, Xuejie; Tan, Xiao

doi:10.4028/www.scientific.net/amm.602-605.353

Cited by 2 publications

(2 citation statements)

References 6 publications

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“…The deviation in the maximum value of the effective turbulent viscosity is 0.4% for TL model and 0.3% for LSY model with 30% and 45% more nodes in the radial and axial, respectively. The capabilities and performance of this code have been demonstrated in Chen et al 22 …”

Section: Numerical Methodologymentioning

confidence: 99%

Numerical simulation of turbulent flow between shrouded contra-rotating disks

Chen

Zhang

Tan

et al. 2016

Advances in Mechanical Engineering

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The turbulent flow between shrouded contra-rotating disks was numerically studied with a two-layer turbulence model and a modified Launder-Sharma low-Reynolds number k-e model. The dissipation rate decrease caused by solid body rotation was considered in the second model. The comparisons of the effectiveness between these two turbulence models for capturing the critical radius of flow structure transition and reproducing the flow velocity measurements data were presented. For the flow between shrouded disks rotating at the same speed but in opposite senses, that is, the angular velocity ratio of the two disks equals to 21, the Stewartson-type flow structure is found in the cavity. For the flow with one disk rotating more slowly than the other, Stewartson-type flow coexists with Batchelor-type flow, that is, Batchelor-type flow occurs radially outward of the stagnation point where two opposing boundary layer flows meet, and Stewartson-type flow occurs radially inward. The stagnation points near the slower disk move radially outward as the angular velocity ratio decreases toward 21. Theory of rotating fluids with the presence of centrifugal and Coriolis forces stemming from the disk rotation is employed to manifest the flow structure transition mechanisms as the rotation ratio of the disks is varied. The source of the earlier transition to turbulent flow in counter-rotating disk cavity compared with rotor-stator disk cavity is also explained through the research of instability of the flowing free shear layer formed by the counter secondary circulations. With the aid of the numerical results obtained from the two turbulence models, it is found that a more turbulent flow in the core can destroy the Batchelor-type flow and creates a larger Stewartson-type flow region.

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Section: Numerical Methodologymentioning

confidence: 99%

Numerical simulation of turbulent flow between shrouded contra-rotating disks

Chen

Zhang

Tan

et al. 2016

Advances in Mechanical Engineering

View full text Add to dashboard Cite

show abstract

“…3 In this way, optimizing disk cooling efficiency and disk cavity sealing performance requires profound insight into the inherent flow circulation and the heat transfer characteristics in the disk cavity. 4,5 Turbine disk cavities can be classified into three different modes of configurations: (1) rotor-stator disk cavity modes (one disk stationary and the other one rotating at some rate), (2) co-rotating disk cavity modes (two disks rotating in the same senses), and (3) counter-rotating disk cavity modes (two disks rotating in opposite senses). The flow in rotor-stator cavity was investigated experimentally and numerically by many researchers, such as Se´verac et al, 6 Se´verac and Serre, 7 and Tuliszka-Sznitko et al 8 The non-isothermal cavity conditions were also taken into account in many investigations.…”

Section: Introductionmentioning

confidence: 99%

Effects of the rotation number on flow and heat transfer in contra-rotating disk cavity with superposed flow

Chen

Zhang

2019

Advances in Mechanical Engineering

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The turbulent fluid flow and convective heat transfer in counter-rotating disk cavity with central axial air inflow and radial air outflow are numerically studied based on the finite volume method. Efforts are focused upon the influence of the rotation number Rt on the flow structure, cooling performance, sealing effect, and surface tangential friction characteristics in the cavity. The stagnation point where the radial outward flow along the upstream disk driven by the rotation force meets the radial outward flow along downstream disk driven by the combination of rotation force and inflow inertial force moves from upstream disk wall to the shroud with increasing Rt. At the Rt far smaller than 1, the fluids in the core region between two disks rotate with the upstream disk like a rigid body, and the tangential velocity of the rotating core decreases with the increase of the disk cavity radius, which is different from the Batchelor-type flow. At the Rt larger than 1, the fluids on the upstream disk side rotate like the Batchelor-type flow, while the sandwich rotation disappears in the fluid on the downstream disk side. The temperature on the upstream disk wall increases and then decreases with increasing values of Rt, and the critical value of Rt for the change of temperature variation is assessed to be at about Rt = 0.69. The temperature and radial temperature gradient of the downstream disk wall decrease with increasing Rt. With increasing Rt by increasing the disk rotation rate, the pressures near the downstream disk decrease, while the frictional moments on rotating disks increase. Due to the effect of flow structure, the frictional moment on the upstream disk is smaller than that on the downstream disk.

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Flow Structure Transition inside Contra-Rotating Disk Cavity

Cited by 2 publications

References 6 publications

Numerical simulation of turbulent flow between shrouded contra-rotating disks

Numerical simulation of turbulent flow between shrouded contra-rotating disks

Effects of the rotation number on flow and heat transfer in contra-rotating disk cavity with superposed flow

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