• 한국유체기계학회 논문집
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• 제10권4호
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• pp.47-54
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• 2007

Simultaneous 3-D LDV measurements of the in-cylinder flows of three different engine setups were summarized for the quantification of the flow characteristics in each vertical or horizontal plane, and in entire cylinder volume. The ensemble averaged-velocity, tumble and swirl motions, and turbulent kinetic energy during the intake and compression strokes were examined from the measured velocity data (approximately 2,000 points for each engine setup). The better spatial resolution of the 3-D LDV allows measurements of the instantaneous flow structures, yielding more valuable information about the smaller flow structures and the cycle-to-cycle variation of these flow patterns. Tumble and swirl ratios, and turbulent kinetic energy were quantified as planar and volumetric quantities. The measurements and calculation results were animated for the visualization of the flow, and hence ease to analysis.

• 동력기계공학회지
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• 제3권2호
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• pp.13-19
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• 1999

The purpose of the present experimental study is to apply multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to high-speed flow region within a domestic boiler circulation pump. Two different kinds of flow rate($27{\ell}/min,\;19{\ell}/min$)are selected as experimental condition. A volute casing and Impeller made of transparent Polycarbonate were made for the easy access of the illumination laser via fiber optical line and cylinder lens assembly to the measuring region. A CCD camera is syncronized with AOM to acquire clear original particle images. Optimized cross correlation identification to obtain velocity vectors is implemented by direct calculation of correlation coefficients. The instantaneous and time-mean velocity distribution, velocity profile and kinetic energy are represented quantitatively at the full-scale region for the deeper understanding of the unsteady flow characteristics in a commercial circulation pump.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1995년도 추계학술발표회논문집(1)
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• pp.41-47
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• 1995

A parametric study bas been performed for the various refueling schemes of CANDU 6 reactor loaded with reference DUPIC fuel. The optimum discharge burnup was determined such that the peak bundle power is minimized for the equilibrium core. Based on the results of instantaneous core calculation using patterned random age distributions, it was decided to perform the refueling simulations only for 2-bundle and 4-bundle shift refueling schemes. The 600 FPD simulation has shown that the operational margins of the channel and bundle power to the license limits are 7.9% and 17.1%, respectively, for 2-bundle shift refueling scheme. The 4-bundle shift refueling scheme also satisfies the license limits and the operational margins of the channel and bundle power are 7.1% and 9.8%, respectively. The result of refueling simulation indicate the possibility of using reference DUPIC fuel in current CANDU 6 reactor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.80-82
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• 2004

The single phase switched reluctance motor(SRM) is more simpler and robust in the structure than poly phase SRM. It has the merits that it reduces the switching elements and the energy density per volume is very high. Recently, it has been researched and developed in various types and starting method due to the technique of power electronics and the computer added design. This paper presents a analytical representation of the phase inductance of a single phase SRM, as function of position and current, taking into account the non-linearity of the magnetic circuit. the method is based on Fourier series expansion. Analytical expressions for the calculation of instantaneous phase inductance, flux linkage, coenergy and electromagnetic torque as a function of rotor position and winding currents are derived.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.788-793
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• 2001

Finite element analysis was carried out to investigate the integrity and reliability of boiler module during sea transportation. The boiler module was supported by steel structure to relieve the instantaneous shock from oceanic wave and its primary parts were strengthened with several reinforcements. Finned tube walls which were used in the furnace wall were assumed as orthotropic plates having equivalent material properties. The bank tubes were also equivalently modeled in accordance with ASME B31.1 for the convenience of finite element modeling. The calculation results were compared with the yield stress of the material. In particular, the bank tube stress, which was evaluated by converting the calculated stresses in equivalent tubes into those in original tubes by using the ratio of diameter, was also examined with yield stress.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.686-691
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• 2000

Animation technique from the PIV database is particularly emphasized to give macroscopic and Quantitative description of complex flow fields. As an example, an experimental study was carried out investigate the fundamental (low characteristics of the freezer with the domestic refrigerator. Optimized cross correlation identification to obtain velocity vectors is implemented by direct calculation of correlation coefficients. Image intensifier CCD camera to cope with illumination problem is arranged for the accurate PIV measurement of large flow field. As a results, continuous pictures of the spatial distribution of the instantaneous and time-mean velocity distribution are displayed in real-time sense.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.694-699
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• 2003

Simultaneous measurement with PLIF(Planar Laser-Induced Fluorescence) and Stereo-PIV(Stereoscopic Particle Image Velocimetry) was performed to investigate the structural characteristics of flow field in Rushton Turbine Mixer. Instantaneous 3D velocity fields are measured by two 2K ${\times}$ 2K CCD cameras focused on an object plane with the angular displacement methods while the concentration fields are obtained through the measurement of the fluorescence intensity of Rhodamine B tracer excited by the second pulse of Nd:Yag laser light. Image distortion due to the camera view-angle is compensated by a mapping function. Finally, the spatial structures of turbulent mixing around Rushton turbine were identified by the calculation of cross-correlation fields between the velocity and concentration field.

• 대한전기학회논문지
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• 제37권12호
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• pp.862-871
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• 1988

본 논문에서는 전류제어형 PWM인버터-유도전동이 구동 시스템의 속응제어를 위한 벡터제어시스템을 제시하였다. 벡터제어 특성을 충분히 발휘하기 위해서는 고정자 전류의 숭시치 제어가 가능해야하므로 히스테리시스 제어기를 가진 전류제어형 PWM인버어터를 채택하였고 복잡한 벡터회전 및 연산은 마이크로프로세서를 사용한 소프트웨어로 처리하였다. 제시한 시스템을 디지탈시뮬레이션 및 실험을 통하여 그 특성의 우수함을 입증하였다.

• 한국유체기계학회 논문집
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• 제2권1호
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• pp.35-42
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• 1999

The present experimental study is focused on the application of multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to rotor-stater region within centrifugal turbine pump. Six different kinds of rpm(120, 500, 1000, 1500, 2000 and 2500) are selected as experimental condition. Optimized cross correlation identification to obtain velocity vectors is implemented with direct calculation of correlation coefficients. Fine optical setup concerned with PIV performance is arranged for the accurate PIV measurement of high-speed complex flow. The instantaneous and time-mean velocity distribution and velocity profile are represented quantitatively at the rotor and stator region.

• International Journal of Air-Conditioning and Refrigeration
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• 제8권2호
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• pp.11-22
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• 2000

Holographic interferometric tomography can provide reconstruction of instantaneous three-dimensional gross flow fields. The technique however confronts ill-posed reconstruction problems in practical applications. Experimental data are usually limited in projection and angular scanning when a field is captured instantaneously or under the obstruction of test models and test section enclosures. An algorithm, based on a series expansion method, has been developed to improve the reconstruction under the ill-posed conditions. A three-dimensional natural convection flow around two interacting isothermal cubes is experimentally investigated. The flow can provide a challenging reconstruction problem and lend itself to accurate numerical solution for comparison. The refractive index fields at two horizontal sections of the thermal plume with and without an opaque object are reconstructed at a limited view angle of 80$\circ$. The experimental reconstructions are then compared with those from numerical calculation and thermocouple thermometry. It confirms that the technique is applicable to reconstruction of reasonably complex, three-dimensional flow fields.