• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.564-575
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• 2016

The present study provides numerical simulations to predict the added resistance and ship motion of the KVLCC2 in regular waves using the unsteady Reynolds-Averaged Navier-Stokes (URANS) and 3-D potential methods. This numerical analysis is focused on added resistance and vertical ship motions (heave and pitch) under a wide range of wave conditions at three ship speeds (design, operating and zero speeds). Firstly, the characteristics of the CFD and 3-D potential flow methods are presented to predict added resistance and ship motions in regular waves taking into account various wave conditions at design speed to provide a validation study as well as at operating and zero speeds. Secondly, analyses of added resistance and ship motion with unsteady wave patterns and time history results as simulated by CFD were performed at each ship speed. Systematic validation and verifications of the numerical computations in this study were made against available Experimental Fluid Dynamics (EFD) data including grid convergence tests to demonstrate that reliable numerical results were obtained for the prediction of added resistance and ship motion in waves. Relationships between added resistance, vertical motion and changes in ship speeds were also found.

• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.291-298
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• 2017

In recent years, the increase of secondary controls within vehicles requires a mechanism to integrate various controls into a single device. This paper presents control performance of an integrated magnetorheological (MR) haptic device which can adjust various in-vehicle comfort instruments. As a first step, the MR fluid-based haptic device capable of both rotary and push motions within a single device is devised as an integrated multi-functional instrument control device. Under consideration of the torque and force model of the proposed device, a magnetic circuit is designed. The proposed MR haptic device is then manufactured and its field-dependent torque and force are experimentally evaluated. Furthermore, an inverse model compensator is synthesized under basis of the Bingham model of the MR fluid and torque/force model of the device. Subsequently, haptic force-feedback maps considering in-vehicle comfort functions are constructed and interacts with the compensator to achieve a desired force-feedback. Control performances such as reflection force are experimentally evaluated for two specific comfort functions.