• Proceedings of the KSME Conference
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• 2005.11a
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• pp.48.2-48.2
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• 2005

• Journal of ILASS-Korea
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• v.3 no.1
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• pp.10-18
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• 1998

To investigate the in-cylinder phenomena in a SI engine with 3 valves and pent-roof type combustion chamber, flow fields, fuel distributions, and flame propagations were measured in a single c!'tinder visualized engine. Flow fields were visualized by PTV system during the intake and compression process. Fuel distributions were measured by PLIF at the various engine conditions including the cold and hot engine conditions and the effect of air-shrouded injector on the fuel distribution was investigated also. In addition, flame propagation patterns were characterized.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.10
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• pp.1340-1346
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• 1999

The turbulent shear flow around a surface-mounted vertical fence was investigated using the two-frame PTV system. The Reynolds number based on the fence height(H) was 2950. From this study, it is revealed that at least 400 instantaneous velocity field data are required for ensemble average to get reliable turbulence statistics, but only 100 field data are sufficient for the time-averaged mean velocity information. Various turbulence statistics such as turbulent intensities, turbulence kinetic energy and Reynolds shear stress were calculated from 700 instantaneous velocity vector fields. The fence flow has an unsteady recirculation region behind the fence, followed by a slow relaxation to the flat-plate boundary layer flow. The time-averaged reattachment length estimated from the streamline distribution is about 11.2H. There exists a region of negative Reynolds shear stress near the fence top due to the highly convex (stabilizing) streamline-curvature of the upstream flow. The large eddy structure in the separated shear layer seems to have significant influence on the development of the separated shear layer and the reattachment process.

• Journal of the Society of Naval Architects of Korea
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• v.39 no.3
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• pp.41-47
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• 2002

Turbulent wake behind a ship propeller has been investigated using the adaptive hybrid 2-frame PTV(Particle Tracking Velocimetry). 400 instantaneous velocity fields were measured according to 4 different blade phases and ensemble-averaged to investigate the spatial evolution of the vortical structure of near wake within one propeller diameter downstream. The phase averaged mean velocity fields show the potential wake and the viscous wake formed by the boundary layers developed on the blade surfaces. As the tip vortex evolves downstream, the slipstream is contracted and the turbulent intensity is decreased with viscous dissipation and turbulent diffusion.