• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.3
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• pp.58-65
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• 2004

Thermal and structural finite element analyses were performed for the turbopump turbine bladed disk model with shroud of a liquid rocket engine. The only 1/80 part model was analyzed which consists of 3D eight node isoparametric solid elements. The applied loading history consists of a startup condition with a thermal spike and a steady state. Heat transfer coefficient on the blade was predicted using the commercial Navier-Stokes solver, Fluent. Transient thermal responses during startup and steady states were calculated using a 3D finite element code developed. Maximum stress and shroud tip displacement under the influence of centrifugal and thermal loading were also determined.

• 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.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.107-110
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• 2002

The present study deals with CFD analysis of 'The vortex generators on plastic plate heat exchanger'. When a vortex generator is placed on the heat transfer surface, the flow gets more complex because it entails complicated three-dimensional flows such as separation, reattachment, and recirculation. CFX-5.4, a commercial code utilizing unstructured mesh, has been used as a computational method for solving RANS(Reynolds-Averaged Wavier-Stokes) equations, and the applied turbulence model is $k-{\varepsilon}$ model. In addition, those computational analyses were implemented under various conditions , with or without the vortex generator between two plates, the number, form and the size of vortex generator, and different attack of angle. From the calculated temperature, velocity and pressure distribution, vorticity, wall heat flux and so on under those conditions, this study shows the effect of vortex on heat transfer.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.9
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• pp.1051-1057
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• 2004

A numerical optimization procedure for the shape of three-dimensional channel with angled ribs mounted on one of the walls to enhance turbulent heat transfer is presented. The response surface method is used as an optimization technique with Reynolds-averaged Wavier-Stokes analyses of flow and heat transfer. SST turbulence model is used as a turbulence closure. Computational results for local heat transfer rate show reasonable agreements with experimental data. The pitch-to-height ratio of the rib and rib height-to-channel height ratio are set to be 9.0 and 0.1, respectively, and width-to-rib height ratio and attack angle of the rib are chosen as design variables. The objective function is defined as a linear combination of heat-transfer and friction-loss related terms with weighting factor. Full-factorial experimental design method is used to determine the data points. Optimum shapes of the channel have been obtained in the range from 0.0 to 0.1 of weighting factor.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.6
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• pp.55-61
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• 2019

The purpose of this study was to numerically analyze the heat flow characteristics of an automotive radiator. Heat flow analyses were conducted on the cooling water and outdoor air of the radiator, as well as the temperature distribution of the cooling water after heat transfer. The results of the study revealed that neither heat transfer nor radiator volume was affected by the position of the inlet of cooling water. However, temperature distribution was affected by the position of both the inlet and outlet. In case of heat transfer, three models underwent about 158 kW of heat transfer. The difference in cooling water temperature was about $10^{\circ}C$. In case of pressure drop, the core external air side was reduced to about 1,375 Pa, and the internal cooling water side about 14,570 Pa.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.5
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• pp.187-196
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• 1996

In this study, 3-dimensional finite element model of a diesel engine cylinder head was made to accomplish heat transfer analysis and also thermal stress and deformation analysis. Heat release analysis and Nusselt-Reynolds correlations were applied to determine the convective boundary conditions which are required for heat transfer analysis to calculate temperature distribution. Thermal stress distribution was also investigated from heat transfer analysis results. Steady state temperature and heat flux were measured by using K-type thermocouples and then compared with numerical results to give a guarantee for the propriety of numerical analyses.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.3
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• pp.55-67
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• 1993

In this study, the thermal behavior characteristics of the cylinder block of a small 3-cylinder, 4-stroke gasoline engine were analyzed, using the 3-dimensional finite element method. Before numerical analyses were conducted, the performance test and the heat transfer experiment of the engine were carried out in order to prepare the input data for the computations. Engine cycle simulation was performed to obtain the heat transfer coefficient and the temperature of the gas and the mean heat transfer coefficient of coolant. Temperature fields as a result of steady-state heat transfer were obtained and compared with experimental results measured at specific points of the inner and the outer walls of the cylinder block. The thermal stress and deformation characteristics resulting from the nonuniform temperature distributions of the block were investigated. The effects of the thermal behaviors of the cylinder block on the engine operations and the unfavourable aspects of excessive thermal loading were examined on the basis of the calculated results.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.3
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• pp.538-550
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• 2004

The convection heat transfer coefficients on the top surface of a large liquid petroleum liquid injection(LPLi) engine piston with the oil gallery are analyzed by solving an inverse thermal conduction problem. The heat transfer coefficients are numerically found so that the difference between analyzed temperatures from the finite element method and measured temperatures is minimized. Using the resulting heat transfer coefficients as the boundary condition, temperature of a large LPLi engine piston is analyzed. With varying cooling water temperature, temperature, stress, and thermal expansion of the piston are analyzed and evaluated.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.3
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• pp.311-318
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• 2003

The present work evaluates the effects of mixing vane shape on the flow structure and heat transfer downstream of mixing vane in a subchannel of fuel assembly. by obtaining velocity and pressure fields. turbulent intensity. flow-mixing factors. heat transfer coefficient and friction factor using three-dimensional RANS analysis. Four different shapes of mixing vane. which were designed by the authors were tested to evaluate the performances in enhancing the heat transfer. Standard k-$\varepsilon$ model is used as a turbulence closure model. and. periodic and symmetry conditions are set as boundary conditions. The flow blockage ratio is kept constant. but the twist angle of mixing vane is changed. The results with three turbulence models were compared with experimental data.

• Architectural research
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• v.10 no.1
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• pp.1-11
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• 2008

A Steel column with damaged spray-applied fire resistive material (SFRM) may exhibit reduced structural performance due to the effects of elevated temperature during fire events. Thus, the fire load behavior of steel columns with removed or reduced SFRM needs to be examined to predict the structural damage by fire. FEM analyses were performed for the flange thinning removal models in which the SFRM was reduced as a constant strip in thickness at the top flange of the column. The temperature results for all models obtained from the heat transfer analyses were included as an initial condition in the FEM structural analyses. In this study, the results of analysis show that even small remnants of SFRM led to an effective reduction of temperature at any given fire duration, and improved significantly the axial load capacity of a column as compared to the complete removal cases of SFRM.