• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.1
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• pp.1-13
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• 1995

In order to investigate the effect of liquid balancer in washing machine, we identify the vibration characteristics of suspension system of washing machine and formulate the 4 D. O. F. system dynamic equations. As the washing machine rotates higher speed, it is emphasized to reduce the ecentric force due to unbalanced mass. Nowadays, the most effective cancelling method of eccentric force is known as the usage of liquid balancer. To determine the liquid distribution in liquid balancer, the fluid statics is considered. The system dynamic equations are solved by Runge-Kutta method and represent the good characteristics of real washing machine in X-Y plane. The accuracy of the numerical solution was examined by experiments. The simulation results show that the unbalanced mass has so much influence on vibration magnitude and the rotating shape of spin-basket. But the effect of mass reduction due to the dehydration of the spin-basket has little influence on transient vibration.

• Structural Engineering and Mechanics
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• v.77 no.6
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• pp.765-777
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• 2021

Recently, the plate bending analysis has been interpreted in terms of the tensor's components of curvatures and bending moments by presenting the conceptual perspectives of the Hydrostatic Method of Analysis (HM) and theoretical formulations that combine the continuum mechanics with the graphical statics analysis, the theory of thin orthotropic and isotropic plates, and the elasticity theory. In pursuance of uncovering a genuine formulation of the plate's flexural differential equations, that possess the general-covariance and coordinates-independency. This study had then, tackled various natural and structural problems in both solid and fluid branches of the continuum mechanics in a description of such theoretical and conceptual attainment in uncovering the dimensional independent diffeomorphism covariant partial differential laws.

• Transactions of The Korea Fluid Power Systems Society
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• v.6 no.2
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• pp.1-6
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• 2009

The APU(Auxiliary Power Unit) needs a set of complex pipeline for the fuel supply system where some of the main valves controlling the flow rate consist of the servo valve worked with a torque motor. The input electric current produces an induced magnetic field almost perpendicular to the background magnetic filed generated by fixed permanent magnets. The induced torque deforms the tubular bushing, and directly rotates an armature, which can open and close the valve. In this study, we start from a basic analytic model using a simple electro-magneto-statics, and expand our model to the three-dimensional one computationally applying a commercial code named COMSOL. The result is compared with each other, and reasonable numerical data are obtained for the dynamic behavior and multi-physics system.

• International Journal of Naval Architecture and Ocean Engineering
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• v.5 no.3
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• pp.364-375
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• 2013

Contemporary lectures in undergraduate engineering courses typically focus on teaching major technical knowledge-based theories in a limited time. Therefore, most lectures do not allow the students to gain understanding of how the theories are applied, especially in Naval Architecture and Ocean Engineering departments. Shipyards require students to acquire practical ship design skills in undergraduate courses. To meet this requirement, two lectures are organized by the authors; namely, "Planning Procedure of Naval Architecture & Ocean Engineering" (PNAOE) and "Innovative Ship Design" (ISD). The concept of project-based and collaborative learning is applied in these two lectures. In the PNAOE lecture, sophomores receive instruction in the designing and building of model ships, and the students' work is evaluated in a model ship contest. This curriculum enables students to understand the concepts of ship design and production. In the ISD lecture, seniors learn how to develop their creative ideas about ship design and communicate with members of group. They are encouraged to cooperate with others and understand the ship design process. In the capstone design course, students receive guidance to facilitate understanding of how the knowledge from their sophomore or junior classes, such as fluid mechanics, statics, and dynamics, can be applied to practical ship design. Students are also encouraged to compete in the ship design contest organized by the Society of Naval Architects of Korea. Moreover, the effectiveness of project-based and collaborative learning for enhancing interest in the shipbuilding Industry and understanding the ship design process is demonstrated by citing the PNAOE and ISD lectures as examples.