• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.6 no.6
• /
• pp.879-884
• /
• 2002

There are screw, reciprocating and turbo compressor by structure in an air compressor, essential equipment on he industrial spot. Resently it is wide that the range of turbo compressor's use in gradual, turbo compressor needs high speed rotation of impeller in structure, high rated gearbox and conventional induction motor. This mechanical system increased the moment of inertia and mechanical friction loss. Resently the study of turbo compressor applied super high speed motor and drive, removing gearbox made its size small and mechanical friction loss minimum. In this study we tried to develope variable super high speed motor drive systems for 150Hp, 70,000rpm drect drive Turbo compressor. The result of study is applied to a 150Hp direct turbo compressor and makes it goods.

• Proceedings of the KSME Conference
• /
• 2004.04a
• /
• pp.563-567
• /
• 2004

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.36 no.11
• /
• pp.1063-1071
• /
• 2008

A piezoceramic unimoph actuator can produce a relatively larger actuation force and actuation displacement when a proper compressive load is applied during operation, because the compressive stress causes material nonlinear behavior in the piezoceramic layer and triggers mechanical buckling. In this paper, we examined effects of the actuator under compression on the flapping angle and aerodynamic force generation capability. Effects of wing shape and passive wing rotation angle on the aerodynamic force production were also investigated. The average vertical force acquired by a 2D CFD simulation for an artificial wing showed a good agreement with the measured one by the experiment.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1546-1547
• /
• 2007

휴대용 면역진단 시스템을 구현하기 위하여 설계된 공기주입기로 구동되는 랩온어칩 내의 유체 유동을 컴퓨터 시뮬레이션을 통하여 해석하고, 문제점을 보완할 수 있는 구조로 랩온어칩을 재설계하였다. 공기주입기에서 흘러나오는 공기를 이용해 완충액 저장고 내에 있는 완충액을 토출시킬 때 다량의 기포가 발생함을 시뮬레이션 결과를 통해 알 수 있었다. 완충액 저장고의 내부에 계단형 구조를 삽입함으로서 완충액 이송 시 형성되는 기포를 상당히 억제할 수 있었다. 또한 계단형 구조는 유선을 역행 방지판 쪽으로 분산시켜 역행 방지판의 효율을 높일 것이다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 1999.11a
• /
• pp.482-485
• /
• 1999

This paper proposes a remote supervisory controlling system of air compressor that is controlled by 80196KC microprocessor. In proposed monitoring system, air compressor located in long distance can be controlled In any condition by RS-232 serial communication. Change of data and abnormal signal of it can be also obtained. The validity of the proposed monitoring system is verified through digital simulations and experiments for air compressor driven by induction motor.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.39 no.1
• /
• pp.61-69
• /
• 2015

The objective of this study is to experimentally investigate the mixed flow behaviors and oxygen transfer characteristics of a vertical orifice ejector. The experimental apparatus consisted of an electric motor-pump, an orifice ejector, a circulation water tank, an air compressor, a high speed camera unit and control or measurement accessories. The mass ratio was calculated using the measured primary flow rate and suction air flow rate with experimental parameters. The visualization images of vertically injected mixed jet issuing from the orifice ejector were qualitatively analyzed. The volumetric oxygen transfer coefficient was calculated using the measured dissolved oxygen concentration. At a constant primary flow rate, the mass ratio and oxygen transfer coefficient increase with the air pressure of compressor. At a constant air pressure of the compressor, the mass ratio decreases and the oxygen transfer coefficient increases as the primary flow rate increases. The residence time and dispersion of fine air bubbles and the penetration of mixed flow were found to be important parameters for the oxygen transfer rate owing to the contact area and time of two phases.

• Journal of KSNVE
• /
• v.11 no.2
• /
• pp.187-195
• /
• 2001

승용차 실내소음은 소음의 전달 방법에 따라 구조기인소음(structure-borne noise)과 공기기인소음(air-borne noise)으로 구별된다. 구조기인 소음은 차체에 전달된 외력이 차체를 통하여 전달되고 전달된 차체의 진통이 최종적으로 차실을 이루는 패널의 진동을 일으켜 승객에 전달되는 소음이며 공기기인소음은 발생한 소읍이 공기를 타고 전파되어 차실을 투과하여 승객의 귀에 전달되는 소음을 말한다. 구조기인소음을 일으키는 기진력으로 엔진의 관성 및 폭발력, 노면의 입력, 구동계 진동, 풍력 등이 있다. 발생된 기진력은 엔진 마운트, 서스펜션 등을 통하여 차체에 전달되고 최종적으로 대쉬, 루프 등의 패널을 떨게 만들며 이러한 진동은 50∼500Hz 대역에서 차실 공간의 음향 특성에 따라 가감되어 저주파 실내 소음을 발생시킨다. 500Hz 이상 대역의 실내소음은 일반적으로 공기기인 소음이 대부분을 차치하게 된다.(중략)

• Aerospace Engineering and Technology
• /
• v.7 no.1
• /
• pp.40-48
• /
• 2008

Air mixing system which is composed of air pressure control system, hot pipe system and air mixer, is the facility for mixing hot air($1000^{\circ}C$, 10kg/s) from storage air heater (SAH) and decompressed air($20^{\circ}C$, 15kg/s) from high pressure air supply system. Air pressure control system reduce the pressure of the air, from 32MPa to 3.5 MPa and supply the decompressed air to air mixer. The hot pipe system supply hot air from SAH to air mixer which mix hot with the decompressed air from air pressure control system. Fully mixed air flow rate is 25kg/s and mixed temperature is up to $400^{\circ}C$. So, we can expand the operating envelop of the supersonic ground test facility to low Mach number and low altitude region.

• Proceedings of the KIPE Conference
• /
• 2006.06a
• /
• pp.101-103
• /
• 2006

일반적으로 리니어 구동기나 회전하는 모터를 이용하여 적은 힘으로 증량의 물체를 이송하는 시스템이 개발되어 현자에서 사용되고 있다. 그러나 공기압이나 유압을 사용하는 리니어 구동기나, 회전하는 모터를 사용하기 때문에 Backlash를 비롯한 비선형성이 크기 때문에 성능의 한계를 갖는다. 본 논문은 동기형 리니어 모터를 구동하는 DSP 기반의 힘 제어기를 설계, 제작하고 힘제어를 이용하여 이송하는 시스템을 개발하고 시험한 내용을 보여준다.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.18 no.4
• /
• pp.388-394
• /
• 2009

Precision positioning system with magnetostrictive actuator(MA) has widely used in manufacturing devices to control the positioning accuracy to meet the high load and stroke requirements. It has many advantage in comparison with piezoelectic actuator; high force, high strain, high efficient etc. But, the performance of Terfenol-D, the commercially available magnetostrictive material, is highly dependent on the prestress, magnetic field intensity and temperature. Therefore, thermal strain of magnetostrictive material obstructs precision position control of magnetostrictive actuator, magnetostrictive actuator is need of cooling system. In this paper, cooling system using compressed cold air is developed and proper temperature and velocity of compressed cold air is studied by thermal analysis according to applied current.