• 한국전산유체공학회:학술대회논문집
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• 2009.11a
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• pp.188-192
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• 2009

A massive cavity is generated behind the underwater vehicles, such as marine propellers, pump impellers, nozzles, injectors, torpedoes, etc. when a underwater vehicle moves at very high speed in the underwater. At this point it makes supercavitating flow and the nose, ie., the cavitator is very important fator at the vehicle since it should be surrounded by the cavity. The present work has focused on the simulation of cavitation flow using the new cavitator. The governing equation is the Navier-Stokes equation based on homogeneous mixture model. For the code validation, the results from the present solver have been compared with experiments and other numerical results. A fairly good agreement with the experimental data and other numerical results have been obtained.

• 한국전산유체공학회:학술대회논문집
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• 2009.04a
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• pp.315-320
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• 2009

A computational investigation is conducted on free convection from a thin plate having a surface heat source. The thermal configuration simulates the recently-proposed transparent film heater made of a single-walled carbon nanotube film on a glass substrate. The Navier-Stokes computations are carried out to study laminar free convection from the heater. Parallel numerical experiments are performed by using a simplified design analysis model which solve the conduction equation with the boundary conditions utilizing several existing correlations for convective heat transfer coefficient. Comparison leads to the most suitable boundary condition for the thermal model to evaluate the performance evaluation of a transparent thin-film heater.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.2 s.152
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• pp.93-100
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• 2007

Post swirl stator is an energy saving device to recover rotational energy of the propeller. To optimize the performance of post swirl stator in container vessels, computational fluid dynamics using body force method was introduced. A commercial code Fluent was used in conjunction with body force distributed on the surface of actuator disk which is located in the propeller plane to optimize pitch angle of the post swirl stator blade. This study showed that CFD is an important tool to simulate flow behind ship with propeller, rudder and post swirl stator.

• The KSFM Journal of Fluid Machinery
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• v.6 no.1 s.18
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• pp.44-50
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• 2003

Flow through a turbine flow meter is simulated by solving the incompressible Navier-Stokes equations. The solution method is based on the pseudo-compressibility approach and uses an implicit-upwind differencing scheme together with the Gauss-Seidel line relaxation method. The equations are solved steadily in rotating reference frames, and the centrifugal force and the Coriolis force are added to the equation of motion. The standard $k-{\epsilon}$model is employed to evaluate turbulent viscosity. Computational results yield quantitative as well as qualitative information on the design of turbine flow meters by showing the distributions of pressure and velocity around the turbine blades.

• Journal of computational fluids engineering
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• v.8 no.3
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• pp.56-65
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• 2003

A numerical procedure for analyzing the heat transfer in a regenerative cooling passage of liquid rocket has been developed. The thermal analysis is based on the numerical model of Naraghi〔1〕. The thermodynamic and transport properties of the combustion gases are evaluated using the chemical equilibrium composition. The pressure and heat flux obtained by the isentropic relation are in good agreement with the result of Navier-Stokes equations. The effect of design parameters on heat transfer is addressed for the pressure loss and temperature variation. Also, their constraints in designing the cooling passage are recommended. Finally, in a heated rectangular duct, the effects of secondary flow on heat transfer are scrutinized by the nonlinear k- e -fu of Park et at.〔2〕.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1371-1376
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• 2004

Flow analysis of automobile front-end cooling fan are numerically investigated. The Navier-Stokes equations and the continuity equation are solved in the flow domain. The Reynolds stresses are modelled using the $k-{\varepsilon}$ turbulence model. Flow and pressure characteristics around the fan are investigated. The pressure sharply increases through the fan. Pressure variations on the pressure and suction sides of the fan are well represented in the calculations. The flow streamlines in the blade passage are nearly parallel to the blade.

• Journal of Mechanical Science and Technology
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• v.18 no.9
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• pp.1614-1622
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• 2004

When a High Speed Train (HST) passes through a station with no stop, effects of wind pressure transients caused by this passing train have to be considered for the safety of passengers on the platform and for the possible structural safety problems as well. In Gwangmyeong and Daejeon stations of the Korean high speed railroad, tunnels inside stations for the passing train are proposed to reduce the noise and wind pressure transients to the passengers on the platform. In the present study, transient 3-D full Navier-Stokes solutions with moving mesh to implement train movement are obtained and compared with the results obtained by the towing tank experiment. Investigations on flow phenomena for various train speeds and design modifications are also performed.

• Journal of Ocean Engineering and Technology
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• v.15 no.4
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• pp.46-52
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• 2001

SMAC method, one of the numerical simulation techniques, is modified from the original MAC method for the time-dependent variation of fluid flows. The Navier-Stokes equations for incompressible time-dependent viscous flow are applied, and Also marker particles which present the visualization of fluid flows are used. In this study, two-dimensional numerical simulations of the overtopping are carried out by SMAC method, and the simulation results are visualized, In addition to, motion pictures are made for efficient visualization of the simulation results. This numerical simulation could also be applied to the design of coastal structures as dike and revetment.

• 한국전산유체공학회:학술대회논문집
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• 2001.10a
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• pp.70-75
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• 2001

This paper presents the results of numerical simulation of wind environment and wind coefficient around super high-rise building. The analysis of aerodynamic response due to wind-induced forces and wind effect to surrounding buildings is important to high-rise building. This paper simulates the wind force to the high-rise building and wind flow pattern around the high-rise building, and shows the usability of CFD analysis to design process of high-rise building. A Navier-Stokes-Solver (FLUENT) with Quick spatial discretization scheme and RNG $\kappa-\epsilon$ turbulence model has been applied to the computation of the three dimensional turbulent flow.

• 한국전산유체공학회:학술대회논문집
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• 2001.05a
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• pp.121-126
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• 2001

An accelerating flow field through a compressor cascade is studied numerically by unsteady computational simulation. The two-dimensional Navier-Stokes equations for compressible flow is used for the study of unsteady high incidence angle flow, with preconditioning scheme to cover the wide range of Mach number and $\kappa-\omega$ model for the turbulent viscous flow analysis. A DCA(double circular arc) compressor blade is accelerated artificially in this study to understand the unsteady effect by comparing the present results with the existing steady-state experimental and computational results. Also, the accelerating flow field during the starting phase of gas turbine is studied with actual experimental data for the understanding of flow field and performance characteristics at off-design condition.