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
제14권 제3호 (2012년 6월) 15건
학술연구
1.
2012.06
구독 인증기관 무료, 개인회원 유료
In this paper, cycle performance analysis of two-stage compression and one-stage expansion refrigeration system using alternative Freon refrigerants is presented to offer the basic design data for the operating parameters of the system. Pure alternative Freon refrigerant R32, R134a and near NARM(Non-Azeotropic Refrigerants Mixtures) R404A, R407C, R410A and ARM(Azeotropic Refrigerant Mixtures) R507A were used working fluids in this study. The operating parameters considered in this study included evaporation temperature, condensation temperature, subcooling degree, superheating degree, mass flow rate ratio of inter-cooler. The main results were summarized as follows : The COP of two-stage compression and one-stage expansion refrigeration system increases with the increasing subcooling degree and mass flow rate ration of inter-cooler, but decreases with the increasing evaporating temperature, condensing temperature and superheating degree. Therefore, subcooling degree, mass flow rate ratio of inter- cooler of two-stage compression and one-stage expansion refrigeration system using alternative Freon refrigerants have an effect on COP of this system.
4,000원
2.
2012.06
구독 인증기관 무료, 개인회원 유료
The human activity of most what kind of form belongs in the vibration. For example, we listen in order for the eardrum membrane to vibrate and for the light to fluctuate in order and we make see. The breath is relating in the vibration of the lung and walking becomes accomplished in compliance with the periodic oscillatory motion of the arm and the leg. With technical advancement joins in, the vibration of the passenger cars is influencing many in sound arresting and riding in a car feeling of the vehicle. Gradually the field where the vibration isolation and decrement technique automobile plan is important according to being turning out, the necessity of the measurement which the passenger cars vibration is accurate and analysis was augmented.
4,000원
3.
2012.06
구독 인증기관 무료, 개인회원 유료
The quarter car test rig is designed and constructed for testing the performance of a vehicle active suspension system. The performance of the optimal variable structure controller is tested to compare with those of a passive suspension system and the simulation result. The dynamic characteristics of the PCV(pressure control valve) is tested, and based on this result, the lead compensator is designed for reducing the dynamic effects of the PCV. The performance of an active suspension system with the compensator gives almost that of an ideal active suspension system. From the frequency response analysis of which input is a white noise, the active suspension system shows the better performance than a passive suspension system around 1Hz which is the natural frequency of the sprung mass.
4,000원
4.
2012.06
구독 인증기관 무료, 개인회원 유료
An experimental study was performed to determine the thermal conductivities of polymer aqueous solutions under static condition. Pseudoplastic fluids were considered as test fluids. A coaxial cylinder apparatus with a rotating outer cylinder and a stationary inner cylinder was installed to measure the thermal conductivities of the test fluid. First, the thermal conductivity of distilled water was measured to validate the instrument. The experimental water data agreed within 1% of literature values and there was no effect of outer cylinder rotation (shear field). In addition, for polymer aqueous solutions such as aqueous Carboxy-methyl Cellulose solutions, thermal conductivities were also in agreement within 5% of literature values for Carboxy-methyl Cellulose solutions depending on the polymer concentration and temperature.
4,000원
5.
2012.06
구독 인증기관 무료, 개인회원 유료
Study on characteristics of cold temperature separation for cooling of charging air in a vortex tube
The diesel engine uses the intercooler for cooling of charging air by the turbo-charger. But the cooling efficiency of the intercooler which is influenced by the vehicle speed is decreased in low vehicle speed. If the vortex tubes are substituted for the intercooler due to their many intrinsic benefits in many industrial fields as parts for refrigerating machines, the cooling efficiency could be advanced in the low speed range. In this study, a counter-flow type of vortex tube is employed to investigate the temperature separation characteristics with various geometric configurations for optimization of charging air cooling. A parametric study was conducted to evaluate the performance of the vortex tube with various geometric structures and operating inlet pressures. The results show that variation of the cold exit orifice hole diameter significantly influences the energy separation between two exits.
4,000원
6.
2012.06
구독 인증기관 무료, 개인회원 유료
The thermal conductivity for the ground heat exchanger installed in the local facilities of greenhouse area at JangSu-Gun in Jeollabuk-Do was analyzed experimentally. For measuring the thermal conductivity of the ground heat exchanger, a bore hole was punched at the size of diameter 150mm, depth 160m. And a closed-type heat exchanger of high density polyethylene at the size of diameter 40mm was installed vertically. The heated water by an electric heater was circulated through the ground heat exchanger with a pump. The inlet/outlet temperatures and the flow rates of this water are measured and the thermal conductivity was calculated. The experimental results were as follows. The inlet/outlet temperatures of the ground heat exchanger were increased rapidly until 7 hours, then they were increased gently and the difference of inlet/outlet temperature was maintained at about 4.5℃. The thermal conductivity calculated by the line source theory was 2.207W/mK.
4,000원
7.
2012.06
구독 인증기관 무료, 개인회원 유료
In order to calculate the energy basic unit for industry complex, Statistic Analysis were carried out. As a result of analysis, this paper propose new calculated fuel basic unit, electric power basic unit and energy basic unit. Also shows that overall mean fuel basic unit decrease, electric power basic unit increase and energy basic unit decrease as compared with the Notification No. 2009-29 of the Ministry of Knowledge Economy, that the rates of basic unit change of facility investment business type are all increase and the rates of basic unit change of energy intensive & labor-intensive business type are all decrease.
4,000원
8.
2012.06
구독 인증기관 무료, 개인회원 유료
This study analyzes lifes and damages at two automotive grills in use through the structural analyses with fatigue. As maximum equivalent stress in case of aftermarket grill frame becomes smaller more 15 times than horizontal grill frame, aftermarket grill is shown to be more stable. The lowest damage becomes 2968 in case of ‘SAE bracket history’ with the severest change of load at aftermarket grill. As it becomes smaller more 5 times than horizontal grill frame, aftermarket grill has more durability. Among the cases of nonuniform fatigue loads, ‘Sample history’ with the slowest change of load becomes most unstable in case of horizontal grill frame but ‘SAE bracket history’ with the severest change of load becomes most stable in case of aftermarket grill frame. The structural result of this study can be effectively utilized with the design of automotive grill frame by investigating prevention and durability against its damage.
4,000원
9.
2012.06
구독 인증기관 무료, 개인회원 유료
The loop thermosyphon has been designed and tested for cooling several hundreds watt of heat. This cooling system is consisted of copper block, condenser which is fabricated with tubes and fins and transport lines. In this research, operational characteristics and limitation of the loop thermosyphon were investigated as a function of fill charge ratio, thermal load, vapor temperature and effective head. The experimental results shows that the heat transfer limitation is dominated by vapor temperature and effective head. Also, the correlation for the heat transfer limitation is presented and showed good agreement. The evaporating heat transfer coefficient is affected by vapor temperature and heat flux, but the fill charge ratio and liquid head are minor factor.
4,000원
생산기술
10.
2012.06
구독 인증기관 무료, 개인회원 유료
Generally it is needed to have a multi stage drawing operation to increase a drawing ratio. So, this study is about the hydraulic circuit design of the 3 stage deep drawing machine. As the drawing ratio is large or deep, the quality of deep drawing products are affected more by the force and velocity of the press cylinder. Therefore using the computer simulation, the pressure reponses which are related to the force and velocity of press cylinder are analysed, and the design of the hydraulic circuit are proposed. The results of simulation shows that it correspond to experiments and have good feasibility. Proposed hydraulic circuit can be used to improve the quality of a deep drawing products.
4,000원
11.
2012.06
구독 인증기관 무료, 개인회원 유료
In the study, space cooling performance of air source heat pump(ASHP) was evaluated in a pilot house. The ASHP, which provide for floor heating, domestic water heating and space cooling/heating, shows cooling capacity of 14.0 kW, when COP of ASHP was 3.21 based on test performance of KS C 9306. Test results shows that cooling capacity was depended on frequency of the compressor. The variable refrigerant flow rate for cooling were supplied into diverse room by using LEV. The COP at setting room temperature of 26℃ was 6.3% higher than the COP at that of 24℃, when the spending time in operation was decreased as 21.2%.
4,000원
12.
2012.06
구독 인증기관 무료, 개인회원 유료
A capsule is the device for irradiation test of nuclear materials and fuels in HANARO. The instrumentation cables are sealed tightly by brazing at the top of the capsule. In this study, the integrities at the brazing of both Inconel 600 and STS 310 materials were confirmed by tensile test, survey of damage on coating, and measurement of insulation resistance. At tensile test, brazing areas were not damaged but the thermocouples themselves were broken on both the materials. At flame heat test, the coating of STS 310 material was maintained without damage but the brittle fracture on Inconel 600 material was observed. Insulation resistances were confirmed to be satisfactory in case of both the materials. In this analysis, the thermocouple was expanded by 0.81mm on the direction of y-axis and the tube was contracted by 0.57mm on the direction of x-axis. As the result, cracks might be occurred with thermal stresses. EDX spectrum analysis showed that the BAg-1 filler metal formed a thin reaction layer on the surface of brazed metal.
4,000원
13.
2012.06
구독 인증기관 무료, 개인회원 유료
Self-piercing riveting(SPR) is a sheet joining method that can be used for materials which are difficult or unsuitable to weld, such as aluminum alloy and different steel sheet metals. No pre-drilled hole is needed for SPR; the rivets are pushed directly into the sheets clamped together between a blank holder and a die in a press tool. In this paper, self-piercing rivet and anvil were designed for four joining conditions with dissimilar sheet metals. SPR was simulated by using commercial FEM code DEFORM-2D. In simulation of SPR process, various strengths of self-piercing rivet were considered. The mechanical properties could be determined by tensile test for quenched rivets and sheet metals. The designs of rivet and anvil were modified by comparisons of simulated results.
4,000원
14.
2012.06
구독 인증기관 무료, 개인회원 유료
According to a statistics, a number of traffic accident by bridge pier and independent fixed object crash accident has been increased. we evaluated a car damage and passenger injury through vehicle accident reconstruction test of independent fixed object crash accident. A damage of crash accident car based on accident investigation report was similar to demage of 27km/h reconstruction test car, and therefore we can find the speed of crash accident car is 20km/h～30km/h. It is very low that the skull fracture and injury possibility of AIS 4 above in 37km/h and 27km/h reconstruction test car. It is very high that injury possibility in 70km/h reconstruction test car. Also, it is not high that impact of the driver and passenger's lower body(thigh, shin, ankle) in 37km/h and 27km/h reconstruction test car. On the other hand, it is very high that impact of head, chest and thigh of the driver and passenger in 70km/h reconstruction test car.
4,000원
15.
2012.06
구독 인증기관 무료, 개인회원 유료
4,000원
