• 한국정밀공학회지
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• 제17권2호
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• pp.161-168
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• 2000

In this paper, machining characteristics of glass for HDD media are researched. Nowadays HDD media are used globally as a data storage device. In generally, it is machined by the lapping. But the lapping process time is long and the productivity is low. In this reason, 1 examined the possibility of ELID grinding of glass fur HDD media. If the machining process of HDD media can be changed to ELID grinding, a product cost will be largely saved. The machines used in this experiment were a special rotary type grinder and a normal rotary grinder. The one has an air bearing spindle, the other has not. Experimental results show the possibility of highly efficient grinding and mirror surface can be achieved by the ELID grinding.

• 한국군사과학기술학회지
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• 제4권1호
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• pp.137-146
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• 2001

According to the advanced development of Light Weight Torpedo, the overall items related with the parachute type and gore layout and air stabilizer of the parachute for fixed and rotary wing aircraft are described in this paper. Also, the drag-area which should satisfy the firing envelope, parachute inflation characteristics, stability of parachute and torpedo in airdropping, water entry impact on torpedo and parachute constituted the principle design factors. The important trial and errors occurred in the step of performance of the parachute for fixed and rotary wing aircraft are investigated and analyzed.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2001년도 제23회 KOSCO SYMPOSIUM 논문집
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• pp.142-152
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• 2001

Three Lab-scale combustors of different types were made to observe some basic phenomena of fuel combustion in the combustors ; grate type combustor, rotary kiln and FBC. The aims were to introduce how to simulate the combustion behaviors in the real plants by utilizing the reduced apparatuses and characterize the combustors relating to some important parameters such as fuel size, water contents, bed temperature, rotating speed of kiln, flow rate. The mean carbon conversion time and the flame propagation rate were adopted for the quantitative analysis.

• 융복합기술연구소 논문집
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• 제2권2호
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• pp.49-54
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• 2012

These conventional reciprocating compressor(reciprocating type compressor) or household refrigerators and car air conditioning rotary compressor, rotary compressor, has been used by a reciprocating piston torque variability and the deepening of the vibration problem, the suction valve and discharge valvein this study, as a result of the losses in the current use of the scroll compressor, scroll compressor with the features of low noise, high efficiency, small size, light weight, has increased. fixed Scroll(fixed scroll) scroll compressor with orbiting scroll (rotating scroll) vibration experiments were performed in order to identify the vibration characteristics of the structure of the Analysis was performed using the commercial finite element program(ANSYS) for the sake of comparison, the experimental results using a finite element model of research about the natural vibration characteristics due to a material change.

• Smart Structures and Systems
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• 제17권5호
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• pp.837-857
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• 2016

In the present study, for first time the size dependent vibration behavior of a rotating functionally graded (FG) Timoshenko nanobeam based on Eringen's nonlocal theory is investigated. It is assumed that the physical and mechanical properties of the FG nanobeam are varying along the thickness based on a power law equation. The governing equations are determined using Hamilton's principle and the generalized differential quadrature method (GDQM) is used to obtain the results for cantilever boundary conditions. The accuracy and validity of the results are shown through several numerical examples. In order to display the influence of size effect on first three natural frequencies due to change of some important nanobeam parameters such as material length scale, angular velocity and gradient index of FG material, several diagrams and tables are presented. The results of this article can be used in designing and optimizing elastic and rotary type nano-electro-mechanical systems (NEMS) like nano-motors and nano-robots including rotating parts.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1998년도 추계학술대회 논문집
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• pp.235-241
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• 1998

Flow characteristics of a compressible gas flow through a rotating disc-type rotary valve are investigated experimentally under various conditions. It is known that the mass flow rate through poppet valves of 4-stroke cycle engines and through piston valves of 2-stroke cycle engines decrease with increase in engine speed. Rotary valve is one means by which air maybe made to flow intermittently through a pipe. In this paper a exhaust system simulator of engine was used to experimentally analyzer the decrease inflow rate at high rotation speeds and to determine what variables, other than rotational speed, give rise to the observed behaviour. These variables have been included in an empirical equation which is representative of the measured flow characteristics.

• 한국광학회지
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• 제5권3호
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• pp.431-436
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• 1994

가시광선과 근적외선에서 광학유리 및 액체의 굴절률을 정밀측정하기 위하여 Littrow 프리즘을 이용한 자동시준형 분광굴절률 측정장치를 설계, 제작하였다. 먼저 여러가지 측정변수를 변화시켜 측정정확도를 분석하였으며 rotary encoder와 position sensitive detector를 이용한 고분해능 각도측정장치와 항온장치등을 제작하였다. 마이크로 컴퓨터를 사용하여 측정자동화 하였으며 자세한 설계변수와 성능평가 결과를 제시하였다.

• 한국기계가공학회지
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• 제8권4호
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• pp.61-68
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• 2009

This paper presents the numerical analysis of process of sludge drying to know the characteristics of design parameters and develop the new process plant. Finite volume method and $k-{\varepsilon}$ turbulence model were used to analogy the sludge drying furnace. It has been attempted to perform the disposal of sewage sludge such as simple reclaiming and dumping in sea and incineration. Currently, these methods are restricted by national or international government regulations. The drying process is adopted as an effective method for sewage sludge treatment. However sewage sludge makes it difficult to treat with a large volume at the real drying process plant because of its own complicated physical, chemical, and thermal properties. The final design value of moisture content with 10% of the dried sludge can be obtained through the simulated outputs in this study.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.61-64
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• 2002

In this study, It was designed and developed optimal rotary dressing system of centerless grinding using for ferrule machining. Dressing shaft's dropping is calculated by Finite Element Method, and bearing 7206ADB, 7005ADB is selected. Dressing wheel $GC\Box \;200\Box\; G\Box\; m\Box\; V-100^*25^*16$ is selected by pre-research. Also Motor, pulley, belt are selected, 0.4Kw-60Hz, 48.2 mm diameter, 2-5M-730 type, each.

• 한국유체기계학회 논문집
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• 제7권6호
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• pp.7-14
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• 2004

A new electrostatic rotary atomizing painting equipment using air turbine was developed for high transfer efficiency. Based on the overall design requirements of painting equipment, basic design specifications of the equipment parts such as air turbine and atomizing disk ate defined from the present conceptual design model. Air turbine is designed with the section profile of NACA airfoil, and its internal flow field is analyzed by commercial CFD code. Atomizing disk is designed to achieve the ligament type spray of paint with the use of visualization technique. Various experiments and tests are conducted to investigate the spray and the transfer characteristics of newly-designed painting equipment, and the measurement results are compared with the those of conventional painting equipments. The comparison results show the present painting equipment is superior to the conventional ones in the aspects of transfer efficiency and coating surface characteristics.