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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Mechanical Engineers B
Journal Basic Information
Journal DOI :
The Korean Society of Mechanical Engineers
Editor in Chief :
Volume & Issues
Volume 30, Issue 12 - Dec 2006
Volume 30, Issue 11 - Nov 2006
Volume 30, Issue 10 - Oct 2006
Volume 30, Issue 9 - Sep 2006
Volume 30, Issue 8 - Aug 2006
Volume 30, Issue 7 - Jul 2006
Volume 30, Issue 6 - Jun 2006
Volume 30, Issue 5 - May 2006
Volume 30, Issue 4 - Apr 2006
Volume 30, Issue 3 - Mar 2006
Volume 30, Issue 2 - Feb 2006
Volume 30, Issue 1 - Jan 2006
Selecting the target year
Design Optimization of Nozzle Shape for a Jet Fan
Seo Seoung-Jin ; Kim Kwang-Yong ;
Transactions of the Korean Society of Mechanical Engineers B, volume 30, issue 8, 2006, Pages 715~721
DOI : 10.3795/KSME-B.2006.30.8.715
In the present work, nozzle shape of a jet fan is optimized numerically using three-dimensional Reynolds-averaged Navier-Stokes analysis. Standard
model is used as a turbulence closure. Response surface method is employed as an optimization technique. The objective function is defined as maximum throw distance. Three geometric variables, i.e., length and angle of nozzle, and interval between two nozzles, are selected as design variables. As the main result of the optimization, the throw distance has been improved effectively.
A Study on Flow Characteristics of Fountain-pen Nano-Lithography with Active Membrane Pumping
Lee Jin-Hyoung ; Lee Young-Kwan ; Lee Sung-Kun ; Lee Suk-Han ; Kim Youn-Jea ; Kim Hun-Mo ;
Transactions of the Korean Society of Mechanical Engineers B, volume 30, issue 8, 2006, Pages 722~730
DOI : 10.3795/KSME-B.2006.30.8.722
In this study, the flow characteristics of a FPN (Fountain Pen Nano-Lithography) using active membrane pumping are investigated. The FPN has integrated chamber, micro channel, and high capacity reservoir for continuous ink feed. The most important aspect in this probe provided control of fluid injection using active membrane pumping in chamber. The flow rates in channel by capillary force are theoretically analyzed, including the control of the mass flow rates by the deflection of the membrane. The above results are compared with the numerical simulations that calculated by commercial code, FLUENT. The velocity of the fluid in micro channel shows linear behaviors. And the mass flows are proportional to the second order function of the pumping pressure that is imposed to the membrane.
A Study on Operation Characteristics of Planar-type SOFC System Integrated with Fuel Processor
Ji Hyun-Jin ; Lim Sung-Kwang ; Yoo Yung-Sung ; Bae Joong-Myeon ;
Transactions of the Korean Society of Mechanical Engineers B, volume 30, issue 8, 2006, Pages 731~740
DOI : 10.3795/KSME-B.2006.30.8.731
The solid oxide fuel cell (SOFC) is expected to be a candidate for distributed power sources in the next generation, due to its high efficiency and high-temperature waste heat utilization. In this study, the 5-cell SOFC stack was operated with pure hydrogen or reformed gas at anode side and air at cathode side. When stack was operated with diesel and methane ATR reformer, the influence of the
and GHSV on performance of stacks have been investigated. The result shows that the cell voltage was decreased with the increase of
due to the partial pressure of fuel and water, and cell voltage was more sensitive to
. Next, the dynamic model of SOFC system included with ATR reformer was established and compared with experimental data. Based on dynamic model, the operation strategy to optimize SOFC-Reformer system was suggested and simulated.
Performance Analysis on a Multi-Pass Multi-Branch Heat Exchanger According to Pass Arrangement
Kim Min-Soo ; Lee Kwan-Soo ;
Transactions of the Korean Society of Mechanical Engineers B, volume 30, issue 8, 2006, Pages 741~748
DOI : 10.3795/KSME-B.2006.30.8.741
This paper numerically investigates the effects of pass arrangement on the flow distribution characteristics and the performance of a multi-pass multi-branch heat exchanger. Four cases of pass arrangement (2, 4, 6, 8 pass) are chosen to select a proper pass arrangement. A JF factor is used as an evaluation characteristic value to consider the heat transfer and the pressure drop. The present results indicate that 4-pass heat exchanger shows the best performance, and the design parameters in 4-pass heat exchanger are optimized. The design parameters are the locations of the inlet, outlet and separator, and are optimized using a response surface methodology. The JF factor of the optimum model is increased by about 9.3%, compared to that of the reference model (2-pass heat exchanger).
Effects of Outer Tube Length on Pool Boiling in an Annulus with Closed Bottoms
Kang Myeong-Gie ;
Transactions of the Korean Society of Mechanical Engineers B, volume 30, issue 8, 2006, Pages 749~755
DOI : 10.3795/KSME-B.2006.30.8.749
To improve pool boiling heat transfer in an vertical annulus with closed bottoms, the length of an outer tube has been changed from 0.2m to 0.6m. For the test, a heated tube of 19.1mm diameter and water at atmospheric pressure have been used. Annular conditions are made using glass tubes fabricated around the heated tube. The gap size of the annulus is 3.65mm. To elucidate effects of the outer tube length on heat transfer results of the annulus are compared with the data of a single unrestricted tube and the annulus with wider gap size of 6.35mm. Throughout the tests much higher heat transfer coefficients are observed for the annulus of 3.65mm gap size comparing to the other two cases. The change in the outer tube length results in much variation in heat transfer coefficients. Moreover, with shortening the length of outer tube the possibility of the CHF occurrence can be removed.
Study of Operation Strategy for Hybrid PEM Fuel Cell and Supercapacitor
Park Kwang-Jin ; Ji Hyun-Jin ; Bae Joong-Myeon ;
Transactions of the Korean Society of Mechanical Engineers B, volume 30, issue 8, 2006, Pages 756~763
DOI : 10.3795/KSME-B.2006.30.8.756
PEMFC has several technical problems such as water management, long term stability and performance degradation as. PEMFC has been studied not only to solve water management, but also to generate power in stable manner to system by using a hybrid system with auxiliary energy storage device. The purpose of this study is to couple PEMFC with supercapacitor to make a hybrid system and to design and test control strategies for stable power generation in case of changing output power. The polarization curve and dynamic behaviors while changing power were investigated to find out characteristics of PEMFC stack. A DC/DC converter was fabricated in order to increase fuel cell and supercapacitor voltage and to charge supercapacitor. We found that the operation strategy 2 was recommended to the system because of solving water management problem and increasing the dynamic behavior.
An Experimental Study on the Thermal Performance Measurement of Vertical Borehole Heat Exchanger(BHE)
Lim Kyoung-Bin ; Lee Sang-Hoon ; Soung Nak-Won ; Lee Chang-Hee ;
Transactions of the Korean Society of Mechanical Engineers B, volume 30, issue 8, 2006, Pages 764~771
DOI : 10.3795/KSME-B.2006.30.8.764
Knowledge of ground thermal properties is most important for the proper design of large BHE(borehole heat exchanger) systems. Thermal response tests with mobile measurement devices were first introduced in Sweden and USA in 1995. Thermal response tests have so far been used primarily for in insitu determination of design data for BHE systems, but also for evaluation of grout material, heat exchanger types and ground water effects. The main purpose has been to determine insitu values of effective ground thermal conductivity, including the effect of ground-water flow and natural convection in the boreholes. Test rig is set up on a small trailer, and contains a circulation pump, a heater, temperature sensors and a data logger for recording the temperature data. A constant heat power is injected into the borehole through the pipe system of test rig and the resulting temperature change in the borehole is recorded. The recorded temperature data are analysed with a line-source model, which gives the effective insitu values of rock thermal conductivity and borehole thermal resistance.
Experimental Study on Manufacturing of Insulation Vacuum Glazing and Measurement of the Thermal Conductance
Lee Bo-Hwa ; Yoon Il-Seob ; Kwak Ho-Sang ; Song Tae-Ho ;
Transactions of the Korean Society of Mechanical Engineers B, volume 30, issue 8, 2006, Pages 772~779
DOI : 10.3795/KSME-B.2006.30.8.772
Window is a critical component in the design of energy-efficient buildings. To minimize the heat loss, insulation performance of the glazing has to be improved. Manufacturing of vacuum glazing has been motivated by the possibility of making windows of very good thermal insulation properties for such applications. It is made by maintaining vacuum in the gap between two glass panes. Pillars are placed between them to withstand the atmospheric pressure. Edge covers are applied to reduce conduction through the edge. Accurate measurements have been made of the radiative heat transfer, the pillar conduction and the gas conduction using a guarded hot plate apparatus. Vacuum glazing is found to have low thermal conductance roughly below
. Among the heat transfer modes of residual gas conduction, conduction through support pillar and the radiative heat transfer between the glass panes, the last one is the most dominant to the overall thermal conductance. Vacuum glazing using very low emittance AI-coated glass has an overall thermal conductance of about
Optimum Header Design for the Uniform Distribution of Two Phase Flow in the Evaporator
Choi Chi-Woong ; Kim Moo-Hwan ; Cho Nam-Soo ; Lee Jang-Suk ; Lee Jang-Ho ;
Transactions of the Korean Society of Mechanical Engineers B, volume 30, issue 8, 2006, Pages 780~787
DOI : 10.3795/KSME-B.2006.30.8.780
Several types of different header designs are numerically studied to have uniform distribution of two phase flow in the evaporator header having multi-channels. The different geometries include the inlet tube position into the header and the width of header. In the numerical calculation, two types of two-phase model such as homogeneous model and VOF(Volume Of Fluid) model are employed. In this study, the mal-distribution number,
, is newly defined to evaluate the averaged level of the flow distribution in the whole passes of the evaporator. As results, two phase flow in the header can be visualized using post-processing of numerical results. Furthermore, the optimum position of the inlet tube into the header and the width of header can be proposed for the better distribution of refrigerant(R-134a) flow.
The Effects of Advanced Reburning with SNCR on NO
and CO Reduction
Lee Chang-Yeop ; Kim Dong-Min ; Baek Seung-Wook ;
Transactions of the Korean Society of Mechanical Engineers B, volume 30, issue 8, 2006, Pages 788~795
DOI : 10.3795/KSME-B.2006.30.8.788
From the view of the environmental protection against the use of fossil fuels, the great of efforts have been exerted to find an effective method which is not only pollutant reduction but also high thermal efficiency. Reburning is a useful technology in reducing nitric oxide through injection of a secondary hydrocarbon fuel. In this paper, an experimental study has been conducted to evaluate the hybrid effects of reburning and selective non-catalytic reaction (SNCR) on
reduction from oxygen-enriched LPG flame. Experiments were performed in flames stabilized by a co-flow swirl burner, which was mounted at the bottom of the furnace. Tests were conducted using LPG gas as main fuel and also as reburn fuel. The paper reported data on flue gas emissions, temperature distribution in furnace and various heat fluxes at the wall for a wide range of experimental conditions. Overall temperature in the furnace, heat fluxes to the wall and
generation were observed to increase by oxygen-enriched combustion, but due to its hybrid effects of reburning and SNCR,
concentration in the downstream has considerably decreased.
On the Problem of Using Mixing Index Based on the Concentration Dispersion
Suh Yong-Kweon ;
Transactions of the Korean Society of Mechanical Engineers B, volume 30, issue 8, 2006, Pages 796~805
DOI : 10.3795/KSME-B.2006.30.8.796
In this study, the problem of using the mixing index as a measure of the mixing performance for a certain flow field has been discussed. The flow model subjected to this study is the two-dimensional unsteady lid-driven cavity flow. The transport equation for the concentration within the cavity was solved by using the finite volume method where the convective terms are discretized with the central difference scheme. It was shown that both the concentration dispersion and the mixing index depend highly on the initial distribution of the concentration, and therefore the mixing index obtained from the concentration dispersion equation loses its universal applicability.
Behavior of a Heavy Particle in the Shear Flow Near a Flat Wall
Jeong Jae-Dal ; Cho Seong-Gee ; Lee Chang-Hoon ;
Transactions of the Korean Society of Mechanical Engineers B, volume 30, issue 8, 2006, Pages 806~817
DOI : 10.3795/KSME-B.2006.30.8.806
The motion of a small rigid particle in the shear flow near a stationary flat wall is investigated in the context of Stokes flow. The lift force proposed by Saffman and later modified by Mclaughlin and Mei is considered in the prediction of the particle motion far away from the wall. Later, the expression of the lift force is modified to take into account the effect of wall. In the analysis, gravity, lift and drag acting on a small rigid particle near the wall are taken into account. Both analytical and numerical results for the terminal velocities, distances from the wall and trajectories of the particle are presented. In addition, we extended the present analysis to turbulent near-wall flow in the vicinity of the wall.
Performance Evaluation of a Main Coolant Pump for the Modular Nuclear Reactor by Computational Fluid Dynamics
Yoon Eui-Soo ; Oh Hyoung-Woo ; Park Sang-Jin ;
Transactions of the Korean Society of Mechanical Engineers B, volume 30, issue 8, 2006, Pages 818~824
DOI : 10.3795/KSME-B.2006.30.8.818
The hydrodynamic performance analysis of an axial-flow main coolant pump for the modular nuclear reactor has been carried out using a commercial computational fluid dynamics (CFD) software. The prediction capability of the CFD software adopted in the present study was validated in comparison with the experimental data. Predicted performance curves agree satisfactorily well with the experimental results for the main coolant pump over the normal operating range. π Ie prediction method presented herein can be used effectively as a tool for the hydrodynamic design optimization and assist the understanding of the operational characteristics of general purpose axial-flow pumps.