Disturbance-Field Decomposition in a Transversely Forced Swirl Flow and Flame

In advanced gas turbine technology, lean premixed combustion is an effective strategy to reduce peak temperature and thus, NO[Formula: see text] emissions. The swirler is adopted to establish recirculation flow zone, enhancing mixing and stabilizing the flame. Therefore, the swirling flow is dominant in the combustor flow field and has impact on the vane. This paper mainly investigates the swirling flow effect on the turbine first stage vane cooling system by conducting a group of numerical simulations. Firstly, the numerical methods of turbulence modeling using RANS and LES are compared. The computational model of one single swirl flow field is considered. Both the RANS and LES results give reasonable recirculation zone shape. When comparing the velocity distribution, the RANS results generally match the experimental data but fail to at some local area. The LES modeling gives better results and more detailed unsteady flow field. In the second step, the RANS modeling is incorporated to investigate the vane film cooling performance under the swirling inflow boundary condition. According to the numerical results, the leading edge film cooling is largely altered by the swirling flow, especially for the swirl core-leading edge aligned case. Compared to the pressure side, the suction side film cooling is more sensitive to the swirling flow. Locally, the film cooling jet is lifted and turned by the strong swirling flow.

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Enhancement of heat transfer by turbulent decaying swirl flow

Energy Conversion and Management ◽

10.1016/s0196-8904(99)00030-8 ◽

1999 ◽

Vol 40 (13) ◽

pp. 1365-1376 ◽

Cited By ~ 57

Author(s):

M Yilmaz ◽

Ö Çomakli ◽

S Yapici

Keyword(s):

Heat Transfer ◽

Swirl Flow ◽

Enhancement Of Heat Transfer

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Electrochemical study of mass transfer in decaying annular swirl flow Part II: Correlation of mass transfer data

Journal of Applied Electrochemistry ◽

10.1007/bf00251259 ◽

1995 ◽

Vol 25 (1) ◽

Cited By ~ 13

Author(s):

S. Yapici ◽

M.A. Patrick ◽

A.A. Wragg

Keyword(s):

Mass Transfer ◽

Swirl Flow ◽

Electrochemical Study ◽

Transfer Data ◽

Flow Part

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Fluid Force Moment on the Backshroud of a Francis Turbine Runner in Precession Motion

Journal of Fluids Engineering ◽

10.1115/1.4001618 ◽

2010 ◽

Vol 132 (5) ◽

Cited By ~ 2

Author(s):

Bingwei Song ◽

Hironori Horiguchi ◽

Yumeto Nishiyama ◽

Shinichiro Hata ◽

Zhenyue Ma ◽

...

Keyword(s):

Flow Model ◽

Swirl Flow ◽

Francis Turbine ◽

Leakage Flow ◽

Fluid Force ◽

Disk Rotation ◽

Leakage Flow Rate ◽

Turbine Runner ◽

Force Moment ◽

Axial Clearance

The fundamental characteristics of rotordynamic fluid force moment on the backshroud of a Francis turbine runner in precession motion were studied using model tests and computations based on a bulk flow model. The runner is modeled by a disk positioned close to a casing with a small axial clearance. An inward leakage flow is produced by an external pump in the model test. The effects of the leakage flow rate, the preswirl velocity at the inlet of the clearance, and the axial clearance on the fluid force moment were examined. It was found that the fluid force moment encourages the precession motion at small forward precession angular velocity ratios and the region encouraging the precession motion is affected by the preswirl velocity. Through the comparisons of the fluid force moment with and without the rotation of the disk, it was found that the normal moment without the disk rotation did not have the effect to encourage the precession motion. Thus, the swirl flow due to disk rotation was found to be responsible for the encouragement of the precession motion.

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