• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.10
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• pp.3272-3281
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• 1996

The flow analysis method which had been developed for the numerical calculation of 3-dimensional, incompressible and turbulent flow within an axial compressor was extended to the flow field within centrifugal impeller. In this method based on the SIMPLE(Semi Implicit Method Pressure Linked Equations) algorithm, the coordinate transformation was adopted and the standard k-.epsilon. model using wall function was used for turbulent flow analysis. The calculated flow fields have agreed very well with measurement results. Especially, 3-dimensional and viscous flow characteristics including secondary flows, jet-wake flow and decreased pressure rise along impeller passage, which can't be predicted by inviscid Q3D calculation were predicted very reasonably.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1636-1640
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• 2006

SMAC method, one of the computational fluid dynamics techniques, is modified from the original MAC method for the time-dependent variation of flow analysis. The Navier-Stokes equations for incompressible time-dependent viscous flow are applied, and also marker particles that present the visualization of flow analysis are used. In this study SMAC technique is used to analyze the flow behavior in the water-filling of virtual channel. Then by changes of diameter of two ingates, the change of velocity and discharge when two ingates are filled the water to virtual channel are simulated. As a result, water-filling flow pattern in the virtual channel is simulated very well. Therefore, this numerical simulation will also be applied for the design of structures as open flume and porous breakwater.

• Journal of computational fluids engineering
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• v.17 no.1
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• pp.29-35
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• 2012

Fluid-Structure Interaction analysis of a circular cylinder surrounded by incompressible turbulent flow is presented. The fluid flow is modeled by incompressible Navier-Stokes equations in conjunction with large-eddy simulation for turbulent vortical flows. The circular cylinder is modeled as elastic continuum described by elasto-dynamic equation of motion. Finite element method based approach is utilized for unified formulation of fluid-structure interaction analysis. The magnitude and frequency of structural response is analysed in comparison to the driving fluid forces.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.7
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• pp.916-923
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• 2000

Numerical study of three-dimensional turbulent flow in a forward curved centrifugal fan is presented. Standard $k-{\varepsilon}$ turbulence model and non-orthogonal curvilinear coordinates arc used to consider the turbulent flow field and complex geometry. Finite Volume approach is adopted for discretization scheme and structured grid system is used to help convergence. Multiblock grid system is used for flow field and divided into five domains that are inlet, outlet, impeller, tip clearance and scroll. It is assumed that the flow field is steady and incompressible. These numerical results are compared with the experimental data inside a rotor and at the fan outlet. Most important flow features are captured through this numerical approach. Finally details of flow field inside a fan are described and analyzed.

• The KSFM Journal of Fluid Machinery
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• v.10 no.4
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• pp.61-70
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• 2007

Numerical analysis of three dimensional incompressible turbulent flows in LNG marine high pressure drop control valves was carried out by using the CFD-ACE from ESI-Group. In this study, flow characteristics of control valves with complex flow fields including cavitation effect were investigated. Simulation was performed on five models of control valve that had different orifice diameters of anti-trim and the size of valve. Comparing newly designed control valves for controling the occurrence of cavitation with the conventional valve, new valves showed a improved flow pattern with almost no cavitation.

• 한국전산유체공학회:학술대회논문집
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• 1998.05a
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• pp.99-109
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• 1998

This paper describes the analysis of flow and aeroacoustic field around a car-like body. The governing equations, 3-D unsteady incompressible Navier-Stokes equations, are solved with the iterative time marching scheme. The Chimera grid technique has been applied to efficiently simulate the flow around the side-view mirror, After the flow field analysis has been converged, the aerodynamic noise analysis of the side-view mirror has been performed by solving Ffowcs Williams and Hawkings equation. From the present numerical simulation, the A- and C-pillar vortex are evidently shown and the aerodynamic noise level induced by the side-view mirror is predicted to about 100dB.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2001.05a
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• pp.21-27
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• 2001

This paper describes numerical analysis of the impulse turbine with fixed guide vanes, a high performance bi-directional air turbine having simple structure for wave energy conversion. The numerical analysis of the 2-dimensional incompressible viscous flow based on the full Reynold-averaged Navier-Stokes equations which was made to investigate the internal flow behavior. Numerical results are compared with experimental data obtained by T.Setoguchi laboratory. As a result, as suitable choice of design factor has been clarified with the understanding of the internal flow from the numerical analysis.

• The KSFM Journal of Fluid Machinery
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• v.4 no.3 s.12
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• pp.14-20
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• 2001

Numerical analysis of the three dimensional turbulent flow field in a complex valve trim is carried out to confirm the possibility whether this simulation tool can be used as a design tool or not. The simulation of the incompressible flow in a glove valve is performed by using the commercial code. CFD-ACEA utilizes the finite volume approach as a discretization scheme, and the pressure-velocity coupling is made from SIMPLEC algorithm in it. Four flow cases of the control valve are investigated, and the valve flow coefficient for each case is compared with the experimental data. Simulation results show a good agreement with the experiments, and it is observed that the cavitation model improves the simulation results.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.695-696
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• 2002

Three-dimensional blood flow in the sac of the KTAH(Korean total artificial heart) is simulated using fluid-structure interaction model. The aim of this study is to delineate the three-dimensional unsteady-blood flow in the sac of KTAH. Incompressible viscous flow is assumed for blood using the assumption of Newtonian fluid. The numerical method employed in this study is the finite element software called ADINA. Fluid-structure interaction model between blood and sac is utilized to represent the deformation of the sac by the rigid moving actuator. Three-dimensional geometry of cactus type KTAH is chosen for numerical model with prescribed pressure boundary condition on the sac surface. Blood flow is generated by the motion of moving actuator and strongly interacts with the solid material surrounding blood. High shear stress is observed mainly near the inlet and outlet of the sac.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.551-556
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• 2001

The filling pattern technique based on the finite element method and Eulerian mesh advancement approach has been developed to analyze incompressible transient viscous flow with free surfaces. The governing equation for flow analysis is Navier-Stokes equation including inertia and gravity effects. The penalty and predictor-corrector methods are used effectively for finite element formulation. The flow front surface and the volume inflow rate are calculated using the filling pattern technique to select an adequate pattern among four filling patterns at each triangular control volume. Using the proposed numerical technique, the collapse of a dam has been analyzed to predict flow phenomenon of fluid and the predicted front positions versus time have been compared with the reported experimental result.