• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.3
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• pp.111-116
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• 1987

The accurate prediction of the ship wave resistance is very important to design ships which operate satisfactorily in a wave environment. Thus, work should continue on development and validation of methods to compute ship wave patterns and wave resistance. Research efforts to improve the prediction of ship waves and wavemaking resistance are categorized in two major areas. First is the development of higher-order theories to take account of the nonlinear effect of the free surface condition and improved analytical treatment of the body boundary condition. Second is the development of direct numerical methods aimed at solving body and free-surface boundary conditions as accurately as possible. A new formulation of the slender body theory for a ship with constant speed is developed by Maruo. It is quite different from the existing slender ship theory by Vossers, Maruo and Tuck. It may be regarded as a substitute for the Neumann-Kelvin approximation. In present work, the method of asymptotic expansion of the Kelvin source is applied to obtain a new wave resistance formulation in fluid of finite depth. It takes a simple form than existing theory.

• Journal of the Korean GEO-environmental Society
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• v.14 no.11
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• pp.33-46
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• 2013

Recently, the projects which are to increase the capacity of the flood control are being actively performed because of the abnormal climate changes throughout the country. In this study, the regression analysis was performed using both Kelvin model and the real settlement measured at the crest of the existing concrete face rockfill dam(CFRD) to estimate the long-term deformation behavior characteristics such as creep which occurs without additional load. In addition, the effects on changes in physical properties (E, G, K) of the dam construction materials by deformation characteristics of the dam were evaluated, and the reasonable stability analysis method of the dam was proposed to obtain the long-term stability considering the changes in physical properties induced by the long-term deformation behavior in case of heightening the existing dams.

• Advances in nano research
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• v.8 no.3
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• pp.229-244
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• 2020

In this paper, modified Kelvin's model has been used to analyze the orthotropic vibration frequencies of single walled carbon nanotubes with clamped-clamped and clamped-free boundary conditions. For this system the governing equation is developed with wave propagation approach. Armchair, zigzag and chiral structures are considered for the vibrational analysis to investigate the effect of different modes, in-plane rigidity and mass density per unit lateral area. Throughout the computations, on decreasing the length-to-diameter ratios, the frequencies of said structure increases. In addition, by increasing three different value of in-plane rigidity resulting frequencies also increase and frequencies decrease on increasing mass density per unit lateral area. The results generated using computer software MATLAB to furnish the evidence regarding applicability of present model and also verified by available published literature.

• Journal of Ocean Engineering and Technology
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• v.22 no.5
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• pp.1-6
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• 2008

A kinematics model of a ship wake in the presence of surface waves generated by wind is presented. It was found that a stationary wave structure behind a ship covered a wedge region with the angle at the top of the wake and that only divergent waves were present in a ship wake instead of both the longitudinal and cross-waves, which are known as the Kelvin model. Ship motion at some angle to wind waves can cause an essential asymmetry of the wake, compressing its windward half.

• Journal of ILASS-Korea
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• v.1 no.1
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• pp.44-54
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• 1996

A theoretical and experimental study was carried out on the prediction of drop size distribution of the pressure swirl atomizer. Drop size distribution was obtained by using maximum entropy formal ism. Several constraints in the form of the definition of mean diameter were used in this formulation in order to avoid the difficulties of the estimating source terms. In this study $D_{10}$ was only introduced into the formulation as a constraint. A drop size obtained by using linear Kelvin-Helmholtz instability theory was considered as an unknown characteristic length scale. As a result, the calculated drop size was agreed well with measured mean diameter, particularly with $D_{32}$. The predicted drop size distribution was agreed welt with experimental data measured wi th Malvern 2600.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.2
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• pp.259-264
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• 2003

One Clausius inequality based on an apparatus with a single thermal reservoir is reviewed. Some intricate issues regarding the apparatus are brought up and therefore a preferred way to interpret the Kelvin-Planck statement is suggested. Then it is shown that another Clausius inequality can be established from a direct application of the proposition regarding the efficiency of a Carnot cycle. The establishment is based on an apparatus with two reservoirs, and the resultant inequality involves the temperature of external reservoir. Finally, a different apparatus which also has two thermal reservoirs is utilized to compare the cyclic integral of the former inequality with the one of the latter resulting in the proof of the former inequality which involves the temperature at the system boundary. The applications and limitations of these two Clausius inequalities are discussed.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.466-471
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• 2004

Efficient numerical finite element analysis of creeping concrete structures requires the use Kelvin or Maxwell chain model, which is most conveniently identified from a continuous retardation or relaxation spectrum, the spectrum in turn being determined from the given compliance or relaxation function. The method of doing that within the context of solidification theory for creep with aging was previously worked out by Bazant and Xi, but only for the case of a continuous retardation spectrum based on Kelvin chain. The present paper is motivated by the need to incorporate concrete creep into the recently published microplane model M4 for nonlinear triaxial behavior of concrete, including tensile fracturing and behavior under compression. In that context. the Maxwell chain is more effective than Kelvin chain. because of the kinematic constraint of the microplanes used in M4. Determination of the continuous relaxation spectrum for Maxwell chain. based on the solidification theory, is outlined and numerical examples are presented.

• Journal of ILASS-Korea
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• v.2 no.1
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• pp.8-17
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• 1997

A study has been carried out on the instability of a conical liquid sheet by using the linear instability theory. Various analytical methods using the Kelvin-Helmholtz instability theory were tried to examine the wave growth on cylindrical liquid sheets. Cylinderical liquid sheets were extended to the case with the conical sheets. Perturbations due to tangential motion as well as longitudinal one were taken into account. And it was assumed the the breakup occurs when amplitude ratio exceeds exp(12), drop sizes were predicted only by theoretical approach. The predicted drop size agreed well with the measured Sauter mean diameter, $D_{32}$.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.8
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• pp.981-994
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• 2014

Density currents formed by buoyancy discharges from rivers are numerically studied using non-dimensional two layer model including Coriolis acceleration, bottom stress, interfacial friction. Some typical numbers such as Froude number, densimetric Froude number and Kelvin number are obtained and some characteristic scales are defined as a result of non-dimensionalization of the governing equations. Besides the Coriolis effect, the configurations of bottom topography, bottom friction coefficient and interfacial friction are found to significantly affect the propagation of the warm water plume. Frontal position can fastly propagate in the case of large density difference between the two layers and small interfacial friction. Left side boundary current is easily formed under the small interfacial friction. With large Kelvin number, both right and left side boundary currents are formed. Wave-like disturbances and eddies are easily formed under the high Froude number.

• Geomechanics and Engineering
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• v.4 no.1
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• pp.67-78
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• 2012

Soil foundations exhibit significant creeping deformation, which may result in excessive settlement and failure of superstructures. Based on the theory of viscoelasticity and fractional calculus, a fractional Kelvin-Voigt model is proposed to account for the time-dependent behavior of soil foundation under vertical line load. Analytical solution of settlements in the foundation was derived using Laplace transforms. The influence of the model parameters on the time-dependent settlement is studied through a parametric study. Results indicate that the settlement-time relationship can be accurately captured by varying values of the fractional order of differential operator and the coefficient of viscosity. In comparison with the classical Kelvin-Voigt model, the fractional model can provide a more accurate prediction of long-term settlements of soil foundation. The determination of influential distance also affects the calculation of settlements.