• 한국전산유체공학회:학술대회논문집
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• 2006.10a
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• pp.28-29
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• 2006

Computational approaches for the aerodynamic design and optimization are introduced. In this paper the aerodynamic design methods and applications, which have been applied to various aerospace vehicles at Konkuk University, are introduced. It is shown that system approximation technique reduces computational cost for CFD analysis and improves efficiency for the design optimization process.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.6
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• pp.532-540
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• 2008

Recently there are growing interests in calculating aerodynamic characteristics of aircraft configurations with structural deformation using the FSI(Fluid-Structure Interaction) system in which CFD(Computational Fluid Dynamics) and CSD(Computational Structure Dynamics) modules are coupled. In this paper the FSI system comprised of CAD, CFD, CSD, VSI(Volume Spline Interpolation) and grid deformation modules was constructed in order to investigate aerodynamic characteristics of the deformed shape. In the process VSI and grid generation modules are developed to combine CSD and CFD routines and to regenerate the aerodynamic grids for the deformed shape, respectively. For the CFD and CSD analysis, commercial programs FLUENT and NASTRAN were used. As a test model, DLR-F4 wing configuration was chosen and its aerodynamic characteristics were calculated by applying the static FSI system. It was shown that lift and drag coefficients of the wing at mach number 0.75 are reduced to 20.26% and 18.5%, respectively, owing to the structural deformation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.4
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• pp.395-406
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• 2020

The objectives of this study were to develop the optimal structures of recirculating aquaculture tank for improving the removal efficiency of solid materials and maintaining water quality conditions. Flow analysis was performed using the CFD (computational fluid dynamics) method to understand the hydrodynamic characteristics of the circular tank according to the angle of inclination in the tank bottom (0°, 1.5° and 3°), circulating water inflow method (underwater, horizontal nozzle, vertical nozzle and combination nozzle) and the number of inlets. As the angle in tank bottom increased, the vortex inside the tank decreased, resulting in a constant flow. In the case of the vertical nozzle type, the eddy flow in the tank was greatly improved. The vertical nozzle type showed excellent flow such as constant flow velocity distribution and uniform streamline. The combination nozzle type also showed an internal spiral flow, but the vortex reduction effect was less than the vertical nozzle type. As the number of inlets in the tank increased, problems such as speed reduction were compensated, resulting in uniform fluid flow.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.1
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• pp.27-32
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• 2010

In this study, transonic flutter response characteristics have been studied for the AGARD 445.6 wing considering various turbulent models and several angle of attacks. The developed fluid-structure coupled analysis system is applied for flutter computations combining computational structural dynamics(CSD), finite element method(FEM) and computational fluid dynamics(CFD) in the time domain. The flutter boundaries of AGARD 445.6 wing are verified using developed computational system. For the nonlinear unsteady aerodynamics in high transonic flow region, DES turbulent model using the structured grid system have been applied for the wing model. Characteristics of flutter responses have been investigated for various angle of attack conditions. Also, it is typically shown that the current computation approach can yield realistic and practical results for aircraft design and test engineers.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.453-457
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• 2011

In this study, transonic aeroelastic response analyses haw been conducted for the business jet aircraft configuration considering shockwave and flow separation effects. The developed fluid-structure coupled analysis system is applied for aeroelastic computations combining computational structural dynamics(CSD), finite element method(FEM) and computational fluid dynamics(CFD) in the time domain. It can give very accurate and useful engineering data on the structural dynamic design of advanced flight vehicles. For the nonlinear unsteady aerodynamics in high transonic flow region, Navier-Stokes equations using the structured grid system have been applied to wing-body configurations. In transonic flight region, the characteristics of static and dynamic aeroelastic responses have been investigated for a typical wing-body configuration model. Also, it is typically shown that the current computation approach can yield realistic and practical results for aircraft design and test engineers.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.657-662
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• 2011

In this study, aeroelastic performance analyses have been conducted for a 10MW class wind turbine blade model Advanced computational analysis system based on computational fluid dynamics (CFD) and computational structural dynamics (CSD) has been developed in order to investigate detailed dynamic responsed of wind turbine blade Reynolds-averaged Navier-Stokes (RANS) equations with k-${\omega}$ SST turbulence model are solved for unsteady flow problems of the rotating turbine blade model. A fully implicit time marching scheme based on the Newmark direct integration method is used for computing the coupled aeroelastic governing equations of the 3D turbine blade for fluid-structure interaction (FSI) problems.

• Applied Chemistry for Engineering
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• v.30 no.1
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• pp.95-101
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• 2019

The cremation rate of Korea in 2016 was 82.7% which is four times greater than 20.5% in 1994. As increasing the cremation rate gradually, it cause a shortage of cremation facilities resulting in building more cremation facilities to meet the increasing inquiries on cremation or a large amount of fuels for the longer operation of the crematory. In this study, the crematory system optimizing its thermal efficiency characteristics and also responding to increasing inquiries on cremation was proposed in order for solving such problems, In particular, the heat flow characteristics including a heat transfer coefficient by performing a simulation using computational fluid dynamics (CFD) was investigated. The CFD model was validated with on-site experiments for a cremation facility. As a result of the simulation, the fuel consumption decreased nearly 25% and residence time increased in the main combustor. Also, the improved crematory was constructed with an expanded combustor, heat exchanger, second combustion air system, refractory and insulation material. From on-site experiments, the energy consumption was saved to approximately 54.4%, while the burning time reduced nearly 20 minutes.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.606-611
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• 2018

City natural gas is classified flammable hazardous gas and should be secured according to explosion risk assessment determined by Industrial Standard KS C IEC. In this study, leak size, ventilation grade and effectiveness were adopted to the KS C IEC for risk assessment in natural gas supply system. To evaluate the applicability of the computational fluid dynamics (CFD), the risk assessment was studied for four different conditions using hypothetical volume($V_z$) valuesfrom gas leak experiments, KS C IEC calculation, and CFD simulation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.1
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• pp.43-51
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• 2001

Metacomputing system is the environment, which helps the users easily and promptly deal with their jobs. with integration of the distributed computing resources and visualization device. In this research, we have developed a prototype of a special-purpose metacomputing system for simulation in CFD(Computational Fluid Dynamics) field. This system supports the automatic remote compilation, transparent data distribution, the selection of appropriate computing resource, and the realtime visualization. This research can be summarized as following: a study on selecting resource and the integration of component systems. In the research of selecting computing resource, we use the property of CFD algorithm. In the research of realtime visualization. we modify a popular visualizer.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.4
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• pp.469-477
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• 2013

In order to investigate the influence of feed water inequity on the settling performance for parallel arranged upflow sedimentation basin in domestic G_WTP(Water Treatment Plant), CFD(Computational Fluid Dynamics) simulation were employed and ADV(Acoustic Doppler Velocimeter) measurements were carried out. From the results of both CFD simulations and ADV measurements, the differences among inlet flow rates to each inlet structure make turbulent energy dissipation uneven overall sedimentation basin. Especially local velocities in the near of both side wall were observed over the design overflow rate(74.4 mm/min). Also, it was confirmed that this inequity of inlet flow would exert an serious influence on the turbidity of settled water which is out from 8 troughs. Even though experimental velocities in full scale basin about 20% higher than the simulated, the results of ADV measurement were in good accordance with those of CFD simulations.