• Journal of Korean Society for Geospatial Information Science
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• v.19 no.4
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• pp.13-21
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• 2011

The purpose of this study is enhancing CFD model by applying detailed and accurate CFD input data produced from 3D City model and integrating CFD model with 3D city model with OpenGL, 3D city aerodynamic simulation, and visualization tool. CFD_NIMR_SNU model developed by NIMR and SNU and 3D City model produced by NGII were used as input data. Wind flow and pollution diffusion simulator and viewer were developed in this study. Atmospheric environment simulation and visualization tool will save time and cost for urban climate planning and management by enhancing visual communication.

• 한국전산유체공학회:학술대회논문집
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• 2005.04a
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• pp.114-118
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• 2005

CFD simulation was peformed for 2D and 3D flying and rotating frisbees. Multiple reference method(MRF) was utilized to consider the rotation of 3D model. Geometry change of 2D model shows dramatic increase of lift, but 3D simulation results for geometry change show decrease of lift and drag. Ground effect increases the lift of the frisbee being close to ground.

• 한국전산유체공학회:학술대회논문집
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• 2004.10a
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• pp.101-104
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• 2004

CFD simulation is peformed for 2D and 3D frisbees flying at 10m/s. For convenience of simulation, rotation of 3D model is not considered. CFD results show that pitching moment makes the nose down and holes at the leading and trailing edges improve the lift characteristics of the frisbee.

• Aerospace Engineering and Technology
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• v.3 no.1
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• pp.35-44
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• 2004

In this study, one dimensional aerodynamic and structural study of a partial admission turbo pump turbine was performed. A turbine consists of a nozzle, rotor, outlet guide vanes. The aerodynamic characteristics of each component was derived from the governing equation and validated from the CFD calculations. One-dimensional basic design such as velocity triangles was conducted from the mean line analysis and modified from the 2-D and 3-D CFD analysis. The blade profile was determined by the CFD optimization. The thermal stress analysis and structural analysis are needed to be studied in the next design stage.

• Tribology and Lubricants
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• v.25 no.3
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• pp.150-156
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• 2009

Precise leakage prediction for annular type seals of turbomachinery is necessary for enhancing their efficiency and various prediction methods have been developed. As the seal passage is designed intricately, the analysis based on Bulk-flow concept which has been mainly used in predicting seal leakage is limited. In order to improve the seal leakage prediction, full Navier-Stokes Equations with turbulent model derived in the seal flow passage have to be solved. In this study, 3D CFD (Computational Fluid Dynamics) analysis has been performed for predicting leakage of various non-contact type anular seals using FLUENT. Compared to the results by Bulk-flow model analysis, experiment, and 2D CFD analysis, the result of 3D CFD analysis shows improvement in predicting seal leakage, especially for the parallel grooved pump seal.

• Tribology and Lubricants
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• v.25 no.5
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• pp.298-304
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• 2009

An angled labyrinth seal is used for the diaphragm-packing-ring seal design of steam turbine due to its leakage reduction characteristic. CFD analysis using FLUENT has been performed to predict leakage and determine an optimum slanted angle which yields the best leakage reduction. Results show that the optimum value of slanted angle is $-30^{\circ}$ independent of number of labyrinth teeth, inlet pressure, and tooth height to pitch ratio. 3D CFD analysis has been performed for predicting leakage of the angled labyrinth seal. Comparing with the result of 2D CFD analysis, 3D CFD analysis shows 1.4% smaller.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.2192-2197
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• 2003

The purpose of this 3-D numerical simulation is evaluate the application of a commercial CFD code to predict 3-D flow and power characteristics of wind turbines. The experimental approach, which has been main method of investigation, appears to be its limits, the cost increasing with the size of the wind turbines, hence mostly limited to observing the phenomena on rotor blades. Therefore, the use of Computational Fluid Dynamics (CFD) techniques and Navier-Stokes solvers are considered a very serious contender. The flow solver CFX-TASCflow is employed in all computations in this paper. The 3-D flow separation and the wake distribution of 2 and 3 bladed Horizontal Axis Wind Turbines (HAWTs) are compared to Heuristic model and smoke-visualized experimental result by NREL(National Renewable Energy Laboratory). Simulated 3-D flow separation structure on the rotor blade is very similar to Heuristic model and the wake structure of the wind turbine is good consistent with smoke-visualized result. The calculated power of the 3 bladed rotor by CFD is compared with BEM results by TV-Delft. The CFD results of which is somewhat consist with BEM results, under an error less than 10%.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.7
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• pp.906-913
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• 2003

The purpose of this 3-D numerical simulation is to evaluate the application of a commercial CFD code to predict 3-D flow and power characteristics of wind turbines. The experimental approach, which has been main method of investigation, appears to be its limits, the cost increasing with the size of the wind turbines, hence mostly limited to observing the phenomena on rotor blades. Therefore. the use of Computational Fluid Dynamics (CFD) techniques and Navier-Stokes solvers are considered a very serious contender. The flow solver CFX-TASCflow is employed in all computations in this paper. The 3-D flow separation and the wake distribution of 2 and 3 bladed Horizontal Axis Wind Turbines (HAWTs) are compared to Heuristic model and smoke-visualized experimental result by NREL(National Renewable Energy Laboratory). Simulated 3-D flow separation structure on the rotor blade is very similar to Heuristic model and the wake structure of the wind turbine is good consistent with smoke-visualized result. The calculated power of the 3 bladed rotor by CFD is compared with BEM results by TU-Delft. The CFD results of which is somewhat consist with BEM results. under an error less than 10%.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.12
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• pp.1608-1615
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• 2004

CFD data compression methods based on Full-3D and Quasi-1D supercompact multiwavelets are presented. Supercompact wavelets method provide advantageous benefit that it allows higher order accurate representation with compact support. Therefore it avoids unnecessary interaction with remotely located data across singularities such as shock. Full-3D wavelets entails appropriate cross-derivative scaling function & wavelets, hence it can allow highly accurate multi-spatial data representation. Quasi-1D method adopt 1D multiresolution by alternating the directions rather than solving huge transformation matrix in Full-3D method. Hence efficient and relatively handy data processing can be conducted. Several numerical tests show swift data processing as well as high data compression ratio for CFD simulation data.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.97-101
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• 2022

In this study we investigated the gas to solid heat transfer of bubbling fluidized bed bottom ash cooler installed at the Donghae power plant in South Korea. Several different analyses are done through 1-D calculations and 3-D CFD simulation to predict the bottom ash exit temperatures when it exits the ash cooler. Three different cases are set up to have consideration of unburnt carbon in the bottom ash. Sensible heat comparison and heat transfer calculation between the fluidization air and the bottom ash are conducted and 3-D CFD analysis is done on three cases. We have obtained the results that the bottom ash with unburnt carbon is exiting the ash cooler, exceeding the targeted temperature from both 1-D calculation and 3-D CFD simulation.