• Journal of the Korean Institute of Gas
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• v.23 no.6
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• pp.8-16
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• 2019

One of the methods for low-pollution combustion, flue gas recirculation(FGR) is effective to reduce nitrogen oxides and it was applied in CH₄/air premixed counterflow flames to identify the change of flame characteristics and NOx mechanisms. Considering that the mole fraction of the products varied depending on the strain rates, the major products: CO₂, H₂O, O₂ and N₂ were recirculated as a diluent to reflect the actual combustion system. With the application of the FGR technique, a turning point of maximum flame temperature under certain strain rate condition was found. Furthermore as the recirculation ratio increased, the tendency of NO was changed before and after the turning point and the analysis on thermal NO and Fenimore NO production was conducted.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.688-693
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• 2016

This paper describes the parachute dynamics modeling and simulation results for the development of training simulator of a HALO (High Altitude Low Opening) parachute, which is currently in use for military purposes. The target parachute is a rectangular shaped parafoil and its dynamic model is derived based on the real geometry data as the 9-DOF nonlinear equations of dynamics. The simulation was conducted through the moment of inertia and its aerodynamic derivatives to reflect the real characteristics based on the MATLAB/Simulink. In particular, its modeling includes the typical characteristics of the added mass and moment of inertia, which is shown in the strong effects in Lighter-Than-Air(LTA) flight vehicle. The proposed dynamic modeling was evaluated through the simulation under the spiral turning flight conditions of the asymmetric control inputs and compared with the performance index in the target parachute manual.

• Journal of Ocean Engineering and Technology
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• v.31 no.2
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• pp.155-163
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• 2017

Submerged bodies moving underwater behave differently based on their type and assigned mission. This paper describes the dynamic characteristics, including the stability, turning ability, and operational ability, of submerged bodies in relation to design parameters such as the tail cone angle, shape of the control plate, and length of the parallel middle body. A submerged body operated in other countries is adopted as a reference for the dynamic characteristics, its principal dimensions and the shape of the bare hull and appendages are used for comparison. This paper suggests a few candidate hull forms based on changes in the typical design parameters. Finally, the dynamic characteristics for these candidate hull forms are defined.

• Journal of the Korean housing association
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• v.16 no.6
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• pp.93-100
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• 2005

Turning into the 21st century, there are great demands for the diversification of housing style and amenity of housing, which include enhancing community life through proper collective environment. To solve these problems, cohousing has been introduced in Scandinavian countries. A primary goal of cohousing is the desire of residents to live in a socially supportive setting. People can do housework together and also can promote active mutual relationship among residents in the community. Physical feature of cohousing, in combination with social organization factors, nay serve to enhance or support the sense of community sought by residents. In this point of view, the purpose of this study is to consider the characteristics of planning factors applied to the community concept in cohousing. First consideration is to figure out the planning skills on community concept in housing community. Then, by making clear the planning factors on community concept in cohousing through case study, this paper could suggest a possibility of application of cohousing in Korea.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.3
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• pp.109-118
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• 1995

This paper presents a mathematical vehicle model to analyze the dynamic characteristics of a vehicle undergoing braking in a turn. Two kinds of field tests, braking in a steady state turn and braking in a J-turn are performed. Computer simulation results are compared with test results and the braking effect on a vehicle cornering behavior is examined. Also, sensitivity analysis is applied to determine the effect of design parameter changes on the response of vehicle dynamic system.

• 한국전산유체공학회:학술대회논문집
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• 2004.03a
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• pp.42-48
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• 2004

Numerical simulation of viscous compressible flow in turbomachinery cascade involves many problems due to the complex geometry of blade but also flow phenomena. In the present study, numerical investigations have been performed to examine the three-dimensional flow characteristics inside the transonic linear turbine cascades using a commercial code, FLUENT. Multi-block H-type grids are applied to the high-turning turbine rotor blades and comparisons with the experimental data and the numerical results have been done. In addition, the effects of turbulence models on the prediction of the endwall flows are analyzed in the sense of the flow compressibility.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.4
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• pp.34-47
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• 2000

Since carbon fiber epoxy composite materials have excellent properties for structures due to their high specific strength, high specific modulus, high damping and low thermal expansion, the hollow shafts made of carbon fiber epoxy composites have been widely used for power transmission shafts for motor vehicles , spindles of machine tools, motor base, bearing mount for tool up and manufacturing. The molded composite machine elements are not usually accurate enough for mechanical machine elements, which require turning drilling , cutting and grinding. The experiment are surface grinding wheel GC60 to the carbon fiber epoxy composite specimen with respect to staking angle [0]nT , [45]nT, [90]nT on the CNC grinding machine. In this paper, the surface grinding characteristics of composite plate, which are surveyed experimentally and analytically with respect to the grinding force, surface roughness and wheel loading according to the variable depth of cut, wheel velocity and table feed rate are investigated.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.951-956
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• 2005

Since a snake achieves various movements just by a slender body, the mechanism of it is very amazing Many researches have been focusing on a snake like robot and have done for it on the ground. However the meander motion of the snake not only can be done by ground creatures, but also can be done by a water creature such as a sea snake or an eel. Therefore, the purpose of our research is to develop an autonomous underwater robot like the sea snake. As an approach to this goal, we develop an experimental sea snake-like-robot for examining basic characteristics, including propulsion, a turning and other performance. Our developed robot is composed of the head and 4 bodies. Each body equips one servomotor, which is operated with pulse signal. In the head unit, 1- chip-microcomputer, which generates the servomotor control signal for realizing a snake motion and the battery, is equipped. Our robot is covered with a rubber film for the waterproof. Using our developed robot, characteristics of the snake-like-robot moved in water are examined.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.3
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• pp.84-89
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• 2003

The joint method and characteristics of lubricant Impregnated MC nylon and metal are analyzed. Considering the productivity and economics, two materials are Joined with the process of turning, knurling, and induction heating. The Joint strength is determined by adhesion of the melted nylon, the size of knurl, and the interference from the difference of the diameters. The parameters affecting induction heating process are analyzed. The adhesion strength of the melted nylon is measured. Finally the joint strength is analyzed in the environments of low, room, and high temperature. The nylon/metal Joined material is expected to be widely used as the sliding machine elements with good friction and shear strength.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.4
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• pp.36-43
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• 1998

We experimented turning SCM440, called difficult-to-cut materials in general, using tungsten carbon tool(PIO) in order to elevate machinability by a new cutting method. The cutting tool designed and made to study was cooled to -17$0^{\circ}C$ in about 1 minute by liquid nitrogen. Then, we operated cryogenic cutting by cooling tool with liquid nitrogen and stuided the effect about cutting force, chip thickness, surface roughness, behavior of tool wear and cutting temperature. In addition, we investigated the possibility that sur face roughness of workpiece can be predicted analyzing cutting characteristics.