Effect of Jet Inclination Angle and Hole Exit Shape on Vortical Flow Structures in Low-Reynolds Number Jet in Cross-Flow

Yao, Yufeng; Maidi, Mohamed; Yao, Jun

doi:10.1155/2012/632040

Cited by 2 publications

(2 citation statements)

References 17 publications

(22 reference statements)

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“…They concluded that the film-cooling performance is affected by the counter-rotating secondary flow structure downstream of the jet exit in the streamwise injection cases, which can be improved by controlling the strength of the counter-rotating vortex pair. In a recent investigation, Yao et al [33] used the direct numerical simulation (DNS) to predict the flow structures emerged from the interaction of a single square jet issuing into a cross-flow at a velocity ratio of 2.5 and a free stream Reynolds number of 225. Three different kinds of jet geometries have been considered, normal jet, inclined jet at angles of 30 and 60 deg, and round and elliptic jets at an angle of 90 deg.…”

Section: Blowing Ratio Effectsmentioning

confidence: 99%

A Numerical Simulation of the Effects of Swirling Flow on Jet Penetration in a Rotating Channel

Al-Zurfi

Turan

2014

Flow Turbulence Combust

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The hydrodynamic effects of a jet in a swirling cross-flow problem, which is related to gas turbine blades film cooling, were numerically simulated using large eddy simulation with artificial inflow boundary conditions. The purpose of this study is to investigate the effects of swirling flow on a jet effusing from an inclined hole in a rotating channel. The finite volume method and the unsteady PISO algorithm were applied on a non-uniform staggered grid. The work is naturally divided into two main parts. The first part (the swirl flow generator), is a channel rotates axially to generate a turbulent swirling flow at different values of swirl number (SN) of 0.0, 0.15, 0.3, and 0.5 while the second part (test section), is a channel rotating about a parallel axis to investigate the interaction of a square jet with the turbulent swirling flow, generated by the first part, for the prediction of the film cooling under rotating conditions. Four different values of rotation number (Ro) were applied to the test section. The air jet was injected at 30 deg in the streamwise direction, at a velocity ratio of 1.0 and a jet Reynolds number of 4,700, based on the hole width and the jet exit velocity. It was found that the swirling flows primarily displayed the velocity profile of a forced vortex. Weak reverse flow was observed near the main vortex core, which moved in the direction of the swirl and deformed the kidney shape of the Counter Rotating Vortex Pair. As SN increases (SN > 0), the jet trajectory twists in an increasingly x-axis direction due to the centrifugal force effects of the swirl flow, and shifts from the centreline of the channel Flow Turbulence Combust to the right-hand side (Z/D = + 1.5). Also, it was shown that rotation has a strong impact on the mixing behaviour and film cooling effectiveness. Finally, it was concluded that the film cooling decreases rapidly as SN increases.

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Section: Blowing Ratio Effectsmentioning

confidence: 99%

A Numerical Simulation of the Effects of Swirling Flow on Jet Penetration in a Rotating Channel

Al-Zurfi

Turan

2014

Flow Turbulence Combust

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“…The results showed that as the DR increases the penetration of the jet into the cross-flow increases for a constant VR. In a recent investigation, Yao et al [15] simulated a single square jet issuing into a cross-flow at a VR of 2.5 and a freestream Reynolds number of 225 using direct numerical simulation (DNS) approach. Normal jet, inclined jet at angles of 30 • and 60 • , and round and elliptic jets at an angle of 90 • were used.…”

Section: Introductionmentioning

confidence: 99%

A numerical study of rotation effects on jets effusing from inclined holes into a cross-flow

Al-Zurfi

Turan

2015

Journal of Turbulence

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In this work, the complexity of the flow field arising from the impact of the interaction of coolant jets with a hot cross-flow under rotation conditions was numerically simulated using large eddy simulation with artificial inflow boundary condition. The finite-volume method and the unsteady PISO (Pressure Implicit with Splitting of Operators) algorithm were applied on a non-uniform staggered grid. The simulations were performed for four different values of rotation number (Ro) of 0.0, 0.03021, 0.06042, and 0.12084, a jet Reynolds number of 4700, based on the hole width and the jet exit velocity. The air jet was injected at 30 • and 90 • in the streamwise direction with a density ratio of 1.04 and a velocity ratio of 0.5. The flow fields of the present study were compared with experimental data in order to validate the reliability of the LES technique. It was shown that the rotation has a strong impact on the jet trajectory behaviour and the film cooling effectiveness. The film trajectory always inclines centrifugally. Under rotating conditions, the film trajectory departs from the centreline to the left boundary. The deflection becomes greater as Ro increases. Furthermore, it was also found that the injection angle has a strong impact on separation and reattachment behaviour as well as the strength of the penetration into the cross-flow. As it increases, the distribution of the film cooling downstream the jet exit is more non-uniform and the film cooling effectiveness level slightly decreases.

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Effect of Jet Inclination Angle and Hole Exit Shape on Vortical Flow Structures in Low-Reynolds Number Jet in Cross-Flow

Cited by 2 publications

References 17 publications

A Numerical Simulation of the Effects of Swirling Flow on Jet Penetration in a Rotating Channel

A Numerical Simulation of the Effects of Swirling Flow on Jet Penetration in a Rotating Channel

A numerical study of rotation effects on jets effusing from inclined holes into a cross-flow

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