간행물
한국기계기술학회지 KCI 등재 Journal of the Korean Society of Mechanical Technology 韓國機械技術學會誌
- 발행기관 한국기계기술학회
- 자료유형 학술지
- 간기 격월간
- ISSN 1229-604X (Print)2092-0385 (Online)
- 수록기간 1999 ~ 2024
- 주제분류 공학 > 기계공학 공학 분류의 다른 간행물
- 십진분류KDC 550DDC 620
권호리스트/논문검색
제12권 제4호 (2010년 12월) 31건
학술연구
1.
2010.12
구독 인증기관 무료, 개인회원 유료
This paper presents the design for performance improvement of 2-axis cartesian coordinate robot. We cannot obtain the expected design performance unless we select the best-fit linear system for the robot. For this, this paper finds conditions of most suitable to select a LM(Linear Motion) guide and design a 2nd axis arm. By simulation results, the 2nd axis LM guide and the 2nd axis arm structure are confirmed that influence to the deflection of work piece end and the loads on 1 axis LM block. On using LM guide that have capacity near, this paper shows that the maximum load on LM block of 1 axis increases 4.23% and the maximum deflection of work piece end increases 7.95%.
4,000원
2.
2010.12
구독 인증기관 무료, 개인회원 유료
Experimental measurements of flame shape and heat transfer characteristics were performed for impinged inverse diffusion flame(IDF) using propane as a fuel. The purpose of this study is to identify the favorable co-axial inverse diffusion flame structure for impingement heating. The flame consisted of an entrainment zone and mixing and combustion zone. The heat flux which represents heat transfer rate is measured by using a heat flux sensor that is located at the center of the impingement plate. The inverse diffusion flame structure has been classified into six modes. In these modes, several favorable flames for impingement heating were identified. In this study, the parameters are overall equivalent ratio(Φ), nozzle to impingement plate distance(h/d), vertical distance from the stagnation point and Reynolds number(Re) of combustion air.
4,000원
3.
2010.12
구독 인증기관 무료, 개인회원 유료
Due to the global warming problem, diesel engine is becoming an one of the most promising solutions for vehicles in the world. Compared to spark-ignition engines, diesel engines generally have lower unburned hydrocarbon and carbon monoxide, but they also produce still higher levels of NOx and smoke emissions even though using a common-rail injection system. To reduce the diesel emissions, DOC and DPF system have been developed to comply with tighten diesel emission regulations. This paper describes the NOx and smoke emission characteristics of current diesel vehicle with a post injection and plasma after-treatment system. Emissions tests were performed according to New European Driving Cycle mode. Results from these tests show that NOx and smoke emissions with Urea post injection and plasma treatment system is 72% lower than that without the system in the NEDC mode.
4,000원
4.
2010.12
구독 인증기관 무료, 개인회원 유료
Ground source heat pumps are clean, energy-efficient and environment-friendly systems. Although the initial cost of ground source heat pump system is higher than that of air source heat pump, it is now widely accepted as an economical system since the installation cost can be returned within an short period of time due to its high efficiency. In the present study, performances of ground source compound hybrid heat pump system applied to a resort building are simulated. The system design and operation process appropriate for the surrounding circumstance guarantee the high benefit of the heat pump system applied to a resort building. If among several renewable energy sources, ground, river, sea, waste water source are chosen as available alternative energies are combined, COP of the system can be increased largely and hybrid heat pump system can reduced the fuel cost.
4,000원
5.
2010.12
구독 인증기관 무료, 개인회원 유료
Electric motors in electric vehicles has quite fast torque response, thus fast minor feedback loops can be applied for vehicle slip control. In this study, a model following control based slip ratio controller is suggested. This paper introduced a novel strategy of control for wheel slip in electric vehicle by computer simulations. This paper suggested that the control strategy in this paper can control the driving motor torque to drive the wheel on the slippery road surface.
4,000원
6.
2010.12
구독 인증기관 무료, 개인회원 유료
This study was carried out to analyze the effect of wind load on the structural stability of a container crane loading/unloading a container on a vessel. The overturning moment of a container crane under wind load at 75m/s velocity was estimated by analyzing reaction forces at each supporting point. And variations of reaction forces at each supporting point of a container crane were analyzed according to the wind load direction and boom shape.
4,000원
7.
2010.12
구독 인증기관 무료, 개인회원 유료
Recently, A N2 gas generator has become a very popular issue in application to semiconductor production process. An experimental study has been carried out to investigate the production performance as a N2 purity and production of N2 gas generator. The N2 gas generator used a small size system with two adsorption towers and an air compressor as flow rate 20 m3/h. The N2 gas generator system size is width 2270 mm, length 850 mm and height 2135mm. An experimental data has been measured as the variation of a adsorption temperature, adsorption pressure and adsorption time. The results indicate that the N2 gas production increase in case of decreasing adsorption temperature, increasing adsorption pressure and decreasing adsorption time. The N2 purity is highest value of 99.93% when the governor orifice diameter is 0.5 mm.
4,000원
8.
2010.12
구독 인증기관 무료, 개인회원 유료
This study is on the performance characteristics of bubble pump with vertical pipe of different lengths. For the experimental facilities composed of electrical heater used for providing heat source to generate bubble, a vertical tube with Ø4mm diameter, length of 200mm, 300mm, 400mm and 500mm. Storage tank with capacity was of 40 L containing a heat exchanger. The separator and condenser of the air bubble pump were installed separately. The results obtained from this experiment are as follows: there were a few variations of values of temperatures according to vertical pipe lengths of the bubble pump. The mass flow rate was increased by 0.17g/s when it was short as 200㎜ long pipe. But when vertical pipe length was 500㎜, it reached the normal temperature quickly because the slug flow occurred in this case at initial stage. Consequently, it was found that 500㎜ of the vertical pipe length was optimum for best performance of bubble pump.
4,000원
9.
2010.12
구독 인증기관 무료, 개인회원 유료
In this paper, the effect of oxygen component in fuel on the exhaust emissions has been investigated for a direct injection diesel engine. It was tested to estimate change of engine performance and exhaust emission characteristics for the commercial diesel fuel and oxygenated blended fuel which has seven kinds of mixed ratio. And, the effects of exhaust gas recirculation(EGR) on the characteristics of NOx emission have been investigated. Ethylene glycol mono-n-butyl ether(EGBE) contains oxygen component 27% in itself, and it is a kind of effective oxygenated fuel of mono-ether group that the smoke emission of EGBE is reduced remarkably compared with commercial diesel fuel, that is, it can supply oxygen component sufficiently at higher loads and speeds in a diesel engine. It was found that simultaneous reduction of smoke and NOx was achieved with oxygenated fuel and cooled EGR method.
4,000원
10.
2010.12
구독 인증기관 무료, 개인회원 유료
A system approach for studying the engine dynamic characteristics requires a cranktrain flexible body dynamic model including crankshaft, connecting rod and piston. By using a multi-body dynamics code, LMS Virtual Lab, rigid body dynamic model and flexible multi-body dynamic model were established. From these models, the dynamic loads acting on the crankshaft were calculated. Rigid model for V12 engine cranktrain with components connected by kinematical constraints was transformed into a flexible model by replacing rigid crankshaft and connecting rods with flexible ones. And to secure the credibility of flexible body model, three kinds of flexible models were tried, i.e. a model with a fully flexible crankshaft, model with a partially flexible crankshaft(1/6 of the whole length), and a partial detailed flexible model(with finer meshes). The results from each model were compared, and a partial detailed model with finer meshes was found to give reasonable stress values within relatively short period of computing time.
4,000원
11.
2010.12
구독 인증기관 무료, 개인회원 유료
This paper presents the design and automatic control methods employed to implement a open-close mechanism for a food compression processor. The automatic open-close mechanism is intended as a robust approach in compressing incoming food that posses a wide range of physical properties. The method is based on the estimation of compression pressure through current measurement. Test results show that the proposed mechanism effectively controls the compression pressure of the processed food which results in enhanced overall system robustness.
4,000원
12.
2010.12
구독 인증기관 무료, 개인회원 유료
Articulation Index(AI) is the one of the evaluating methods for the interior sound of the automobiles. The AI measures the articulation level of the sound in the vehicle cabin as passengers talk to another. In this study, the effects of AI were investigated according to the various structures of tire. As the structures of tire were changed, the road noise of the vehicle tire was measured using objective measurement. From this measurement data, the AI was calculated. The AI of front is larger than that of rear. Increasing the tread hardness of tire or decreasing the apex height the AI is improved.
4,000원
13.
2010.12
구독 인증기관 무료, 개인회원 유료
Articulation Index(AI) is the one of the evaluating methods for the interior sound of the automobiles. The AI measures the articulation level of the sound in the vehicle cabin as passengers talk to another. In this study, the effects of AI were investigated according to the various structures of tire. As the structures of tire were changed, the road noise of the vehicle tire was measured using objective measurement. From this measurement data, the AI was calculated. The AI of front is larger than that of rear. Increasing the tread hardness of tire or decreasing the apex height the AI is improved.
4,000원
14.
2010.12
구독 인증기관 무료, 개인회원 유료
In neutron beam research, it is necessary for the shielding block and experimental equipment a dance floor in a nuclear reactor to travel in a fixed direction with little friction. However, precise travel is difficult to achieve due to factors such as vibration or gear backlash. We have imported air bearings from more developed nations to perform the role of moving instruments. In the beginning, an air bearing for use in three-dimensional measuring instruments similar to an air bearing was used; however, the performance was found to be insufficient. Accordingly, we collected data and conducted reverse engineering on this type of thrust pad. Through this process, it was confirmed that two issues were influencing the performance: the slant of the bottom of the air bearing and the bottom outside edge of the air bearing plate. The air bearing begins to move at 5 bar and moves smoothly without interruption at 7 bar. The result of this process was the development of a thrust pad which is superior in performance to the imported product and is being used in neutron beam research. We anticipate that this air bearing which has been developed will be used for experimental equipment which requires this type of precision in the future.
4,000원
15.
2010.12
구독 인증기관 무료, 개인회원 유료
In this study, the economic efficiency of ground source heat pump systems were analyzed by comparing with the performance of a conventional system which applied to an air-conditioner for cooling and a boiler for heating. The economic assessment was carried out by the method of life cycle cost and payback period. As a result, the operation cost of the ground source heat pump system was reduced by 18% for cooling and 50% for heating throughout the year. The ratio of life operation cost to life cycle cost increased with the increase of the system capacity. In addition, the payback period was analyzed less than 5 years when the capacity of the ground source heat pump system was more than 10 RT.
4,000원
16.
2010.12
구독 인증기관 무료, 개인회원 유료
According to a statistics, in recent three years number of traffic accident and casualty remain stand still while casualty by car to car side crash has been increased. This phenomenon is attributed to the two main factors. One is vehicle structure and the other is vehicle safety regulation which does not appropriately reflect current market situation. The distance from vehicle side door to occupant is kind of short compare to vehicle front to occupant, so the likelihood of occupant injury or death at side crash accident is higher than any other types of accident. Even Korean government runs to evaluate and improve vehicle side impact crashworthiness, this program does not reflect current vehicle fleet cause it is based on vehicle fleet of more than 20 years ago. In this paper, three sets of car to car side impact test have done to evaluate occupant injury probability and aggressivity of SUV to passenger vehicle, and based on this result the way to reduce injury and fatality likelihood at side crash is recommended.
4,000원
17.
2010.12
구독 인증기관 무료, 개인회원 유료
In this study, we modeled a ship or marine structure into a rectangular resistance body and tried to examine surrounding flow characteristics and pressure distributions behind the resistance body experimentally and investigated pressure characteristics by a 3-dimension numerical simulation. As a result, the reattachment point of the mainstream separated from the upper part and proceeding to the rear part was about x/H=6, but by the influence of the negative pressure area formed behind the resistance body and interference of the flow flowed in winding from left and right, the reattachment point of some flows was formed near x/H=1.33. The perpendicular velocity component behind x/H=0 varies in size with the recycle flow shapes formed from the influence of the resistance body, but generally it shows a negative distribution and there is a decreasing pattern as it goes to the down part. We verified the result of the calculation by comparing the velocity distribution of 3-dimension numerical simulation using a commercial software and the PIV(particle image velocimetry) measurements. In the numerical simulation results, the static pressure characteristic behind the resistance body was proportional to the inflow velocity, and the dynamic pressure shows a similar pattern with constant-velocity from the experiment.
4,000원
18.
2010.12
구독 인증기관 무료, 개인회원 유료
Safety is one of the primary concern for passengers riding a vehicle. Since introduction in the 1980's, the ABS(Anti-lock Brake System) has become so popular that now it almost became a necessity in passenger vehicle. ABS system is detects the wheel speed by controlling the amount of hydraulic when the wheel is locked or slipped. In addition, it consists of device with a complex simulation algorithm and the vehicle's hydraulic braking device And it can determine the status of the hydraulic control by detected signals working status of each solenoid.
4,000원
19.
2010.12
구독 인증기관 무료, 개인회원 유료
External gear pumps are the most widely employed source of power in hydraulic applications, allowing good performance and low manufacturing cost. Generally, pumps with involute external gears are most commonly used. The undesired large pressure overshoots or spikes could be excited by virtue of the sudden volumetric change of meshing pockets. In practice, the spikes cause the gear machines to be noisy, inefficient, and have fatigue problems. In order to improve above issues, relief grooves are adopted practically. In this paper, the meshing pressure and the effects of relief groove configurations are considered through CFD analysis.
4,000원
20.
2010.12
구독 인증기관 무료, 개인회원 유료
The relationship between the addition of metallic additives and the geometry of gas metal arc weld deposit were studied by using Φ1.6mm flux-cored wire designed for hypo-eutectic Fe-Cr-C-Si hardfacing. It was found that the addition of metallic additives, such as Mn, Ti, Al and Si, by less than 0.5wt.% of the overall wire weight affected the dilution of weld deposit by changing the metal transfer mode during welding. The lowest dilution for each additives could be obtained at the transition point between spray and short circuit modes. The bead width was considered to be affected by the increase of arc length due to the oxidizing effect and by the molten pool flow behavior due to the Marangoni effect. Among additives, Mn and Al are considered to be effective in increasing bead width by decreasing the sulfur level and by inducing Marangoni flow directly at the molten pool, respectively.
4,000원
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