• East Asian mathematical journal
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• v.1
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• pp.25-33
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• 1985

• Kyungpook Mathematical Journal
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• v.19 no.1
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• pp.75-84
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• 1979

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1418-1423
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• 2004

A parametric study on the interactions of two spheres aligned in the streamwise direction is carried out using an immersed boundary method. The numerical results for the case of single sphere for the range of Re ${\leq}$ 300 are in good agreement with other authors' experimental and numerical results currently available. Then, our main investigation is focused on identifying the change of the vortical structures in the presence of a nearby sphere aligned in the streamwise direction for the range Re ${\leq}$ 220. It turns out that significant changes in physical characteristics are noticed depending on how close the two spheres are. In this paper, not only quantitative changes in the key physical parameters such as the force coefficients, but also qualitative changes in vortex structures are reported and analyzed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.608-609
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• 2008

An alternator which converts mechanical rotating energy into electric energy is an important component of a vehicle. It operates in broad range from 3000 RPM to 18000 RPM. So, sufficient flow rate and low noise are needed in such broad operating range for a cooling fan of this alternator. In current study, the cooling fan of an alternator is developed through DFSS process and numerical analysis. In order to calculate flow rate and noise level, SC/Tetra and FlowNoise S/W are used respectively, for a new developed fan, compared with original model, numerical result shows 3 dBA reduction and measured value shows 4 dBA reduction.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.808-813
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• 2007

We present the numerical characteristics of a new true stress-strain curve acquisition method over a large range of strains by the tensile test and a finite element method through comparing the results obtained by various finite element mesh systems. The method is introduced in detail. The effects of the finite element mesh systems on the results are investigated to show its numerical characteristics of the new method. It is shown that the method is quite robust, implying that it can be used as a special function of the tensile test machines.

• Structural Engineering and Mechanics
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• v.8 no.4
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• pp.343-360
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• 1999

This work applies a structural analysis method based on an analytical solution from the Fourier series which transforms a half-range cosine expansion into a static solution involving plated structures. Two sub-matrices of in-plane and plate-bending problems are also formulated and coupled with the prescribed boundary conditions for these variables, thereby providing a convenient basis for a numerical solution. In addition, the plate connection are introduced by describing the connection between common boundary continuity and equilibrium. Moreover, a simple computation scheme is proposed. Numerical results are then compared with finite element results, demonstrating the numerical scheme's versatility and accuracy.

• 한국전산유체공학회:학술대회논문집
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• 2008.03a
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• pp.143-147
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• 2008

Numerical analysis is performed to find flow and heat transfer characteristics for ring type heat exchanger. 3-D numerical predictions are carried out for the ring type heat exchanger system with Reynolds number varying in the range of 1,000 and 10,000. From the prediction, streamwise velocity, pressure drop, flow rate and heat transfer coefficient are analyzed. It is also found that characteristics of pressure drop and heat transfer generally follow well proportional variations of Re$m^$for the wide range of Reynolds number considered in this study.

• 한국전산유체공학회:학술대회논문집
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• 2008.03a
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• pp.233-238
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• 2008

An alternator which converts mechanical rotating energy into electric energy is an important component of a vehicle. It operates in broad range from 3000 RPM to 18000 RPM. So, sufficient flow rate and low noise are needed in such broad operating range for a cooling fan of this alternator. In current study, the cooling fan of an alternator is developed through DFSS process and numerical analysis. In order to calculate flow rate and noise level, SC/Tetra and Flow Noise are used respectively, for a new developed fan, compared with original model, numerical result shows 3 dBA reduction and measured value shows 4 dBA reduction.

• 한국전산유체공학회:학술대회논문집
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• 2008.10a
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• pp.233-238
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• 2008

An alternator which converts mechanical rotating energy into electric energy is an important component of a vehicle. It operates in broad range from 3000 RPM to 18000 RPM. So, sufficient flow rate and low noise are needed in such broad operating range for a cooling fan of this alternator. In current study, the cooling fan of an alternator is developed through DFSS process and numerical analysis. In order to calculate flow rate and noise level, SC/Tetra and Flow Noise are used respectively, for a new developed fan, compared with original model, numerical result shows 3 dBA reduction and measured value shows 4 dBA reduction.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.2 s.233
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• pp.247-254
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• 2005

A parametric study on the interactions of two spheres aligned in the streamwise direction is carried out using an immersed boundary method. The numerical results for the case of single sphere for the range of $Rs{\le}300$ are in good agreement with other authors' experimental and numerical results currently available. Then, our main investigation is focused on identifying the change of the vortical structures in the presence of a nearby sphere aligned in the streamwise direction for the range $Re{\le}300$. It turns out that significant changes in physical characteristics are noticed depending on how close the two spheres are. In this paper, not only quantitative changes in the key physical parameters such as the force coefficients, but also qualitative changes in vortex structures are reported and analyzed.