Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Society of Marine Engineering
Journal Basic Information
Journal DOI :
Korean Society of Marine Engineers
Editor in Chief :
Volume & Issues
Volume 28, Issue 8 - Nov 2004
Volume 28, Issue 7 - Nov 2004
Volume 28, Issue 6 - Sep 2004
Volume 28, Issue 5 - Jul 2004
Volume 28, Issue 4 - May 2004
Volume 28, Issue 3 - Mar 2004
Volume 28, Issue 2 - Jan 2004
Volume 28, Issue 1 - Jan 2004
Selecting the target year
Laser Hybrid Welding and Laser Brazing Technology
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 691~698
Study on the Laser Hybrid Welding Technology for Shipbuilding
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 699~703
Numerical Simulation of Aeroacoustic Noise at Low Mach Number Flows by Using the Finite Difference Lattice Boltzmann Method
Eun-Ra Kim ; Jeong-Hwan Kim ; Ho-Keun Kang ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 717~727
In this study, we simulate the aerodynamic sounds generated by a two-dimensional circular cylinder in a uniform flow are simulated by applying the finite difference lattice Boltzmann method (FDLBM). The third-order-accurate up-wind scheme (UTOPIA) is used for the spatial derivatives. and the second-order-accurate Runge-Kutta scheme is applied for the time marching. The results show that we successively capture very small acoustic pressure fluctuations with the same frequency of the Karman vortex street compared with the Pressure fluctuation around a circular cylinder The propagation velocity of the acoustic waves shows that the points of peak pressure are biased upstream due to the Doppler effect in the uniform flow For the downstream. on the other hand. it quickly Propagates. It is also apparent that the amplitude of sound Pressure is Proportional to
, r being the distance from the center of the circular cylinder. To investigate the effect of the lattice dependence furthermore a 2D computation of the tone noise radiated by a NACA0012 with a blunt trailing edge at high incidence and low Reynolds number is also investigated.
Performance Characteristics of Refrigeration and Air Conditioning System Using Hydrocarbon Refrigerants
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 728~734
Environmentally friendly refrigerants with zero ozone layer depletion potential are required to be used in refrigerators and air conditioners due to the difficulties related to ozone layer depletion and global warming. A rigorous study for the system performance with new refrigerants having zero ozone layer depletion potential is inevitable before adopting that as a new fluid. The HFC(Hydrofluorocarbon) potential has been recommended as alternatives. In this paper. system performance in the heat pump facilities were studied using R-290, R-600a. R-1270 as an environment friendly refrigerant. R-22 as a HCFC's refrigerant. The experimental apparatus has been set-up as a conventional vapor compression type heat Pump system. The test section is a horizontal double pipe heat exchanger. A tube diameter of 12.70mm with 1.315mm wall thickness is used for this investigation. The test results showed that the COP of hydrocarbon refrigerants were superior to that of R-22 and the maximum increasing rate of COP was found in R-1270. The refrigeration capacity of hydrocarbon refrigerants were higher than that of R-22. The compressor work was obtained with the maximum value in R-1270 and the minimum one in R-22.
An Analysis of the Flow Characteristics in the Tip Clearance of Axial Flow Rotor
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 735~745
A linear cascade of NACA 65-1810 profiles are investigated for tip leakage flow characteristics. and calculation results are compared with experimental result. STAR-CD commercial code was used to solve the three dimensional incompressible Navier-Stokes equation that was adopted for steady flow and high Reynolds
turbulent model. Numerical calculation of a linear cascade is carried out to investigate effect of tip clearance on pitchwise variations of velocity Profiles. and static pressure distributions on the blade surface at spanwise positions. In case of evolution of tip vortex core location. tip vortex geometry and static pressure at the center of the tip vortex core compared with experimental results. Calculation results are agreed well with the experimental data, and validated. The static pressure losses by tip leakage flow at 2% tip clearance were more than those at 1% tip clearance.
A Study on Development of Internet Based Power Management System Using a Microprocessor
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 746~753
In this paper, the Power Management System(PMS) which based on a decision making system according to power strategy is proposed and implemented. PMS is designed to have functions of power monitoring. controlling, synchronizing load sharing and monitoring of driving engine, etc. PMS consists of the internet communication system(ICS). Remote Management System(RMS) and Sensor Driver System (SDS) ICS transmits the monitoring and supervisory data via Internet to Remote Management System(RMS) in real-time SDS detects various power system data on local generator and utility via I/O interface system. I/O interface system receives various status data and outputs control signals. Implemented PMS is tested with dummy signal to verify proposed functions and shows good results. For future study implemented PMS will be tested under real load condition to merchandize.
Experimental Study on Heat Transfer Characteristics of Evaporation using Propylene Refrigerant
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 754~761
In this paper, evaporating heat transfer characteristics in the refrigeration and air-conditioning facilities were studied using the environmentally friendly refrigerants R-1270 (Propylene). R-290 (Propane). R-600a (Iso-butane) and HCFC refrigerant R-22 The test tube was surrounded by an annulus with water flowing counter to the refrigerant. The tube is copper. with an outside diameter of 12.7mm and the wall thickness of 1.315mm. The test results showed that the local evaporating heat transfer coefficients of hydrocarbon refrigerants were superior to that of R-22 and the maximum increasing rate of heat transfer coefficient was found in R-1270. The average evaporating heat transfer coefficient increased with the increase of the mass velocity and it showed the higher values in hydrocarbon refrigerants than R-22 Comparing the heat transfer coefficient of experimental results with that of other correlations. the presented results had agood agreement with the Kandlikar's correlation. This results form the investigation can be used in the design of heat transfer exchangers using hydrocarbons as the refrigerant for the air-conditioning systems.
Fatigue Life Analysis and Cooling Conditions Evaluation of a Piston for Large LPLi Bus Engines
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 762~772
Fatigue life of a Piston for large liquid Petroleum liquid injection(LPLi) bus engines is analyzed considering effects of cooling condition parameters : temperature of cooling water, and heat transfer coefficients at oil gallery and bottom surface of piston head. Temperature of the piston is analyzed with varying cooling conditions Stresses of the piston from two load cases of pressure loading. and pressure and thermal loading are analyzed Fatigue life under repeated peak pressure and thermal cycle is analyzed by the strain-life theory. For the two load cases, required loading cycles for engine life are defined, and loading cycles to failure and partial damages are calculated. Based on the resulting accumulated fatigue usage factors, endurance of the piston is evaluated and effects of varying cooling condition Parameters are discussed.
A Study on the Grade Efficiency of Sturtevant Type Air Classifier
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 773~781
This research was Performed to raise grade efficiency of Sturtevant type air classifier. to treat powder less than
particle produced at the crushing process of the dry aggregates manufacturing system or concrete wastes recycling system. The experimental conditions were in the ranges. 0.85 to 5.15
/s of primary air flow rate. 0.005 to 0.015
/s of secondary air flow rate
of auxiliary blades angle. respectively. for 1.7~3.3 kg/min of the powder feed rate. It was found that the grade efficiency of the air classifier was increased as the baffle plate was attached at the expansion region. and the optimal operating conditions of the air flow rates and the blade angle were obtained. The fractional recovery curves from the experiments were well agreement with the theoretical one of Molerus model.
Effects of Sealing Solution for Anodized Mg-Al Alloys and Its Corrosion Resistance Property
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 782~792
The effects of sealing solution for anodized Mg-Al alloys and their corrosion resistance property were investigated. focusing on the effects of anodizing potentials aluminum contents and sealing solutions. All of the anodized specimens showed better corrosion resistance than that of non-anodized specimens, regardless of applied potentials. It was found that the anodic film formed at 4 V had the best corrosion resistance. The sealing effects were improved by increasing the temperature of distilled water. the pH of solution and the relative intensity ratio of
Fuzzy Control of DC Servo System and Implemented Logic Circuits of Fuzzy Inference Engine Using Decomposition of
-level Fuzzy Set
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 793~800
The purpose of this study is to develope a servo system with faster and more accurate response. This paper describes a method of approximate reasoning for fuzzy control of servo system based on the decomposition of
-level fuzzy sets. We propose that fuzzy logic algorithm is a body from fuzzy inference to defuzzificaion cases where the output variable u directly is generated PWM The effectiveness for robust and faster response of the fuzzy control scheme are verified for a variable parameter by comparison with a PID control and fuzzy control A position control of DC servo system with a fuzzy logic controller is demonstrated successfully.
A Study on Primal-Dual Interior-Point Method
Seung-Won An ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 801~810
The Primal-Dual Interior-Point (PDIP) method is currently one of the fastest emerging topics in optimization. This method has become an effective solution algorithm for large scale nonlinear optimization problems. such as the electric Optimal Power Flow (OPF) and natural 9as and electricity OPF. This study describes major theoretical developments of the PDIP method as well as practical issues related to implementation of the method. A simple quadratic problem with linear equality and inequality constraints
A Study on the Internet Control and Monitoring System using an Embedded System
Haeng-Choon Chun ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 811~817
Recently embedded systems are widely used in various industrial fields as supervisory controller because they have many merits. One of merits seems to be that operating environment of embedded system is the same as development environment using PC. That makes developing and manufacturing period shorten and also proper time to market Most of all machinery have sequential control system for their maneuvering which is composed of relays. contacts. timers. etc. In this paper. software sequential control system is proposed to be able to replace hardware sequential control system by using embedded system A lot of merits by the software sequential control system can be expected in the respect of economic reproduction, intelligent technologies and utilities, And porting of LINUX operating system to embedded system is carried out and device drivers and interface boards for LINUX 05 are designed for controlling air compressor by software Internet remote control and monitoring system of air compressor is implemented with Java script and CGI for these purposes. The experiment for operating air compressor system is taken through internet networks. The results show that developed system can be used for real plant.
A Research on the Characteristics of Spray-Induced Mixing and Thermal Decomposition of Urea Solution in SCR System
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 818~826
The spray-induced mixing characteristics and thermal decomposition of aqueous urea solution into ammonia have been studied to design optimum sizes and geometries of the mixing chamber in SCR(Selective Catalytic Reduction) system. The cold flow tests about the urea-injection nozzle were performed to clarify the parameters of spray mixing characteristics such as mean diameter and velocity of drops and spray width determined from the interactions between incoming air and injected drops. Discrete particle model in Fluent code was adopted to simulate spray-induced mixing process and the experimental results on the spray characteristics were used as input data of numerical calculations. The simulation results on the spray-induced mixing were verified by comparing the spray width extracted from the digital images with the simulated Particle tracks of injected drops. The single kinetic model was adopted to predict thermal decomposition of urea solution into ammonia and solved simultaneously along with the verified spray model. The hot air generator was designed to match the flow rate and temperature of the exhaust gas of the real engines The measured ammonia productions in the hot air generator were compared with the numerical predictions and the comparison results showed good agreements. Finally, we concluded that the design capabilities for sizing optimum mixing chamber were established.
Parametric Study on the Heat Loss of the Reactor Vessel in the Nuclear Power Plant
Jong-Ho Park ; Seoug-Beom Kim ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 827~836
The design parameter of the heat loss for the pressurized water reactor has been studied. The heat loss from the reactor vessel through the air gap. insulation are analysed by using the computational fluid dynamics code, FLUENT. Parametric study has been performed on the air gap width between the reactor vessel wall and the inner surface of the insulation, and on the insulation thickness. Also evaluated is the performance degradation due to the chimney effect due to gaps left between the panels during the installation of the insulation system. From the analysis results, the optimal with of air gap and insulation thickness and the value of heat loss are obtained The results show how the heat loss varies with the air gap width and insulation thickness. The temperature and the velocity distributions are also presented. From the results of the evaluation. the optimal air gap width and the optimal insulation thickness are obtained. As the difference between the predicted heat loss and measured heat loss from the reactor vessel is construed Primarily as losses due to chimney effect. the contribution of the chimney effect to the total heat loss is quantitatively indicated.
First-Order Sensitivities for FACTS Devices using UPFC Ideal Transformer Model
Thomas W. Gedra ; Seung-Won An ;
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 837~846
This paper presents a screening technique for greatly reducing the computation involved in determining the optimal location and types of Flexible AC Transmission System (FACTS) devices in a large power system. The first-order sensitivities of the generation cost for various FACTS devices are derived. This technique requires solving only one optimal power flow (OPF) to obtain sensitivities with respect to FACTS device control variables for every transmission line To implement a sensitivity-based screening technique, we used a new UPFC model, which consists of an ideal transformer with a complex turns ratio and a variable shunt admittance. A S-bus system based on the IEEE 14-bus system was used to illustrate the technique.
A Study on Aerodynamic Analysis and Design of Wind Turbine Blade
Journal of the Korean Society of Marine Engineering, volume 28, issue 5, 2004, Pages 847~852
The wind turbine blade is the equipment converted wind into electric energy. The effect of the blade has influence of the output power and efficiency of wind turbine. The design of blade is considered of lift-to-drag ratio. structure. a condition of process of manufacture and stable maximum lift coefficient, etc. This study is used the simplified method for design of the aerodynamic blade and aerodynamic analysis used blade element method This Process is programed by delphi-language. The Program has any input values such as tip speed ratio blade length. hub length. a section of shape and max lift-to-drag ratio. The Program displays chord length and twist angle by input value and analyzes performance of the blade.