Gyoung-Woo Lee

Characteristics on the Motion Response of a Catamaran Power Yacht

A very good seakeeping vessel is able to operate effectively even in high sea states and also the passengers and the cargos are ensured in good conditions. The motions of a high speed boats are highly influenced by speed and dynamic forces even in encounter frequencies so that the assessment of seakeeping ability of the design craft in an early stage needs to be calculated for all three motions and for all ralative wave headings. In this paper, it concludes that RAO and RMS values of the catamaran`s 3 motion are calculated according as the variation of Beafort scales and ship`s speed. The ship motion response of the catamaran based on the RAO and RMS by encounter angles and speed was calculated.

Control Effect of Hydro-kinetic Force of a Special Rudder attached Flap

The main purpose in having a control surface on a ship is to control the motion of it. It is the important element to determine the maneuvering characteristics of the ship. In this paper, the measured results has been compared with each other to predict the performance characteristics of flapped rudder`s 2-dimensional section at

Analysis on the Pitch Response Spectra of a Catamaran with Bulb

Re

PIV Analysis of Flow around a Submerged Pitch Damping Foil

In this study, a commercial seakeeping program Seakeeper, integrated into Maxsurf, which is based on the linear strip theory was employed to compare the effect of bulbous bow (with/without) on motion response characteristics in a 18-meter catamaran. The seakeeping analyses were conducted at several Beaufort wind conditions such as scale No. 3 (, =0.6m), No. 4 (, =1m) and No. 5 (, =2m) based on ITTC wave spectrum. Pitch motion response spectrum was calculated at Head sea, Head & bow sea and Beam sea as encounter angles. Hull form of a catamaran with bulb showed the maximum 20% decrease of pitch motion response as compared to that of hull form without bulb.

PIV Measurement of Viscous Flow Field in the Wake of Transom Stern

An experimental study is carried out to investigate the near-wake characteristics of a NACA 0018 foil with a flat plate. Two-frame grey-level cross correlation PIV method is used to measure the local flow characteristic around a pitch damping foil to control the vertical motion of high speed crafts in a circulating water channel. The analysis also includes angles of attack 10 and 20 degrees respectively. Reynolds number based on the chord length(C=100mm) of NACA0018 has been applied during the whole experiments. The distance between the foil and the flat plate is D/C=0.5, 1.0 and 1.5 respectively. The channel effect according as the distance between the foil and the flat plate has a close relation with the velocity distributions around the foil. In the wake of 20-degree of attack, the complex turbulent flow and a thick boundary layer are formed due to the processes of vortex generation and dissipation.

On the Flow Characteristics around a Circular Cylinder according as the Water Depth from the Free Surface

An experiment was carried out to figure out the instantaneous flow characteristics in the wake of the transom stern`s 2-dimensional section by 2-frame grey level cross correlation PIV method at

Control Effects of the Hydrodynamic Force of the Submerged NACA0018 arranging in a Row in a Uniform Stream

Re

On the Variation of the Boundary Layer as Hull Surface Roughness

The free surface influenced the wake behind a circular cylinder and its effects were investigated experimentally in a circulating water channel with the variation of water depth. Instantaneous velocity fields were measured in this paper. The measured results has been compared with each other to investigate the flow characteristics of the circular cylinder`s 2-dimensional section at

Estimation of buckling and collapse behaviour for continuous stiffened plate under combined transverse axial compression and lateral pressure

Re

Flow control on the near wake of a circular cylinder attached with control rods

An open water rudder test was carried out to figure out the flow characteristics around a twin rudder at