• Journal of computational fluids engineering
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• v.13 no.1
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• pp.14-20
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• 2008

The flow characteristics around a rudder in open water condition is analyzed by the computational method. Reynolds averaged Navier-Stoke's equation is utilized for the computation. The computational hydrodynamic force coefficients are verified through comparing with the experimental results. The information of these flow characteristics is necessary to predict cavitation and maneuvering performances, to estimate steering gear capacitance, and to get the bending moment which is useful for the structural analysis. The pressure distribution, the three-dimensional flow separation, and the tip vortices are investigated. The pattern of the three-dimensional flow separation is analyzed utilizing a topological rule. The tip vortices are also investigated through a visualization technique.

• 한국전산유체공학회:학술대회논문집
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• 1998.11a
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• pp.185-190
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• 1998

A Numerical simulation on the flow around a Rudder with blowing is performed by Finite Volume Method. The governing equations are three dimensional incompressible Navier-Stokes equation and Continuity equation, Flow field around a finite Rudder including tip vortex is simulated and the change of the lift force by blowing is analyzed.

• The Journal of the Acoustical Society of Korea
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• v.41 no.3
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• pp.268-277
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• 2022

In this study, each component of flow noise source of underwater propeller installed to the scale model of the KVLCC2 is investigated and the effect of each noise source on underwater-radiated noise is quantitatively analyzed. The computation domain is set to be the same as the test section of the large cavitation tunnel in the Korea Research Institute of Ship and Ocean Engineering. First, for the high-resolution computation of flow field which is noise source region, the incompressible multiphase Delayed Detached Eddy Simulation is performed. Based on flow simulation results, the Ffowcs Williams and Hawkings integral equation is used to predict underwater-radiated noise and its validity is confirmed through the comparison with the tunnel experiment result. For the quantitative comparison on the contribution of each noise source, the spectral levels of sound pressure and power levels predicted using propeller tip-vortex cavitation, blade surface and rudder surface as the integral region of noise sources are investigated. It is confirmed that the cavitation which is monopole noise source significantly contributed to the underwater-radiated noise than propeller blades and rudder which is dipole noise source, and the rudder have more contribution than propeller blades due to the influence of the propeller wake.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.3
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• pp.595-609
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• 2015

The wake characteristics of Contra-Rotating Propeller (CRP) were investigated using numerical simulation and flow measurement. The numerical simulation was carried out with a commercial CFD code based on a Reynolds Averaged Navier-Stokes (RANS) equations solver, and the flow measurement was performed with Stereoscopic Particle Image Velocimetry (SPIV) system. The simulation results were validated through the comparison with the experiment results measured around the leading edge of rudder to investigate the effect of propeller operation under the conditions without propeller, with forward propeller alone, and with both forward and aft propellers. The evolution of CRP wake was analyzed through velocity and vorticity contours on three transverse planes and one longitudinal plane based on CFD results. The trajectories of propeller tip vortex core in the cases with and without aft propeller were also compared, and larger wake contraction with CRP was confirmed.