트랜시스 싱글 존 모델을 이용한 멀티 존 에너지 해석 방법

전병기(Jeon, Byung?Ki),김의종(Kim, Eui-Jong) 한국건축친환경설비학회 2016 한국건축친환경설비학회 논문집 Vol.10 No.5

The purpose of this work is to propose a simple single-zone model for analyzing multi-zone cases. Multi-zone models can be defined directly describing the building plan while important simulation data and careful parameterization are required. In contrast, the single-zone model is set in a very simplified manner, so many engineering projects prefer such a model. However, differences between the two models are not yet well investigated, particularly in a quantitative way, and thus the paper tests the differences and proposes possible methodologies to enhance the single-zone model to be closer to the multi-zone model. Thus, the balcony is modeled in detail to account for the solar double transmitted irradiance via windows at both sides of the balcony. Since the solar transmitted irradiance directly influences building loads, a special attention is required. In addition, the internal walls are taken into account in the single-zone model to keep the similar thermal capacity of multi-zone cases. Results show that the proposed single-zone model predicts very similar annual loads with the reference multi-zone model (about 5% error) while the initial single-zone model without the methodologies is far from the reference model (more than 20% error).

최적화 압출성형용 Melting-Single Screw에 관한 유동 기초연구

김재열(Jea Yoel Kim),정효희(Hyo Hee Chung),곽남수(Nam Su Kwc),최승현(Seung Hyun Choi),고명석(Myung Seok Ko),김종문(Jong Mun Kim),홍철(Cheol Hong) 한국트라이볼로지학회 2007 한국트라이볼로지학회 학술대회 Vol.2007 No.11

Extrusion process is process that solid or high viscosity fluid state material can flow melting and mixing process by heating from frictional heat and outside and produce product consecutively. Products that manufacturing of medicine, plastic, iron and ceramics product etc. Single-screw extruder that is used widely in extrusion process mixing effect of material drops than Multi-screw extruder but facility investment rain and working expenses do not cost much and consist of three zones of feeding zone, compression zone and metering zone usually Duplex metering zone need a lot of researches about heat and flow here to heighten design of extrusion process and productivity of process to central part of Single-Screw extruder control.

Study on the Influence of Variation of Contact Arc Zone on the Single-Pass Sawing of Sapphire Wafer

Jianyun Shen,Lang Lu,Yuanyuan Gong,Xipeng Xu 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.9

Single-pass sawing (SPS), a significant cutting process widely used in the manufacturing of optical components in optoelectronic fields, which can greatly improve the quality of products by reducing the proportion of edge chipping. In this paper, the mechanism of SPS was introduced by a novel approach of deep analysis of the variation of the contact arc zone. Setting sapphire wafers as the workpiece, this study performed the comparative experiments in three specific arc zones, which would further make a thorough inquiry on the related machining mechanism. The difficulty degree of machining and the topography of surface quality during SPS process were also analyzed. The difficulty degree of machining was reflected by the sawing force ratio, and the machining surfaces of sapphire wafers were compared by SEM and Digital Microscope. The results indicate that the lower the arc is, the easier it can be machined during SPS. And the best surface quality appears in Arc 2 (arc angle = 20°), which can be set as an excellent reference for the machining of other materials during SPS. The single-pass sawing mechanism is also derived on the basis of the traditional cutting mechanism model, which will further serve as useful references to both the industrial machining and the academia.

Design and Characteristics Analysis of a Novel Single-phase Hybrid SRM for Blender Application

Kwang-Il Jeong,Jin-Woo Ahn 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.5

In this paper, the design and characteristic analysis of a novel single-phase hybrid switched reluctance motor (HSRM) for the purpose of replacing the universal motor in commercial blenders are presented. The proposed motor is easy to manufacture due to its simple yet robust structure with minimized power switches and no torque dead-zone. Moreover, the proposed HSRM is able to deliver a high starting torque as a requirement for blending hard food or even ice. The stator has permanent magnets (PMs) mounted on its inner surface and the rotor has a wide pole arc and salient poles that contribute to its high starting torque profile and the elimination of the torque dead-zone. Finite element method (FEM) is used to analyze the characteristic of the proposed motor. Finally, the prototype is manufactured and its performance is verified through experiments.

A study on the failure load prediction by damage zone method for single-lap bonded joints with dissimilar adherends

Khanh-Hung Nguyen,Jin-Hwe Kweon,Jin-Ho Choi 한국항공우주학회 2008 한국항공우주학회 학술발표회 논문집 Vol.- No.-

A damage zone method based on three-dimensional finite element analysis was proposed to predict the failure loads of single-lap bonded joints with dissimilar composite-aluminum materials. To simulate delamination failure, interply resin layers between any two adjacent orthotropic laminas of composite adherend were assumed with the thickness of one tenth of a composite lamina. Geometrical and material nonlinearity were considered in the analysis. Based on the experimental observation that the failure modes of the specimens were dominated by delamination and debonding, the Ye criterion was applied to account for the out-of-plane failure of composite adherend and the Von Mises strain criterion was applied for the adhesive layer. The failure indices were multiplied to the predicted damage zone as a weight factor and the calculated damage zones were divided by an area or volume considering the joint geometry. Predicted failure loads show deviation within 15% from experimental results for 6 different bonding lengths or adherend thicknesses.

Cohesive Zone Modeling of Crack Propagation in FCC Single Crystals via Atomistic Simulations

Gi Hun Lee,Jang Hyun Kim,Hyeon Gyu Beom 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.4

This paper presents a cohesive zone model of fracture in Cu and Ni single crystals under tension, based on an atomisticanalysis. The molecular-statics approach based on the conjugate-gradient method was used to investigate the crack-growthbehavior at the atomic level. The fracture toughness was evaluated on the basis of energy considerations, and the cohesivetraction was calculated using the J integral and the atomic-scale separation in the cohesive zone. The cohesive traction andseparation curves obtained using computational data from atomistic simulations were compared with the exponential formof continuum mechanics. The results showed that the exponential form satisfactorily represented the cohesive zone propertiesof Cu. However, the cohesive traction and separation curves for Ni were found to deviate from the exponential form inthe softening stage, owing to small-scale nonlinear features near the cohesive zone.

Recombination zone shift in phosphorescent white organic lightemitting devices with single host structure of multi-emission layers

서유석,문대규 한국물리학회 2014 Current Applied Physics Vol.14 No.9

We have investigated the recombination zone in the phosphorescent white organic light-emitting devices with single host structure of multi-emission layers. Blue, green, and orange-red phosphorescent emitters were doped into the separate layers of single host material for fabricating the white devices with multi-emission layers. The electroluminescence spectrum was substantially modified by the shift of the recombination zone that was dependent upon the thickness of the electron transport layer. We investigated the recombination zone shift in terms of electric field distribution and carrier injection. A maximum external quantum efficiency of 15.9% and a maximum power efficiency of 28.9 lm/W were achieved by optimizing the recombination zone.

Hot zone design optimization for YAG single crystal growth

Pete Sihyun Lee,박철우,박재화,강석현,최봉근,심광보 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.3

The YAG crystal growth industry will follow the same path as the semiconductor industry with cost becoming the main driver. Thus, it become imperative that models be developed that can be used for scaling purposes for the design of large YAG crystalgrowth systems. Analysis of thermal phenomena in the crystal growing by induction heating hot zone and resistance heatingcarbon hot zone has been addressed. To grow a good quality, productivity improvement, and large size of YAG crystal growingis shortfalls of current induction heating Czochralski method. The simulation includes the temperature gradient in melt andmelt-crystal interface, growing zone. Resistance heating has stable temperature gradient in melt and higher gradient in meltcrystalinterface which can be controlled by hot zone design change. Power consumption also improved by using lower thermalconductivity carbon insulation materials.

Failure Load Prediction by Damage Zone Method for Single-lap Bonded Joints of Carbon Composite and Aluminum

Nguyen, Khanh-Hung,Kweon, Jin-Hwe,Choi, Jin-Ho SAGE Publications 2009 Journal of composite materials Vol.43 No.25

<P>A damage zone method based on 3D finite element analysis was proposed to predict the failure loads of single-lap bonded joints with dissimilar composite-aluminum materials. To simulate delamination failure, interply resin layers between any two adjacent orthotropic laminas of composite adherend were assumed with a thickness of one-tenth of a composite lamina. Geometrically nonlinear effects due to the large rotation of the single-lap joint were included in the analysis. Analysis also considered the material nonlinearity of the aluminum adherend due to the stress exceeding yield level. Based on the experimental observation that the failure modes of the specimens were dominated by delamination and debonding, the Ye-criterion was applied to account for the out-of-plane failure of composite adherend and the Von Mises strain criterion was applied for the adhesive layer. The failure indices were multiplied to the predicted damage zone as a weight factor and the calculated damage zones were divided by an area or volume considering the joint geometry. Predicted failure loads show deviation within 18% from experimental results for nine different bonding lengths or adherend thicknesses.</P>

Design and Characteristics Analysis of a Novel Single-phase Hybrid SRM for Blender Application

Jeong, Kwang-Il,Ahn, Jin-Woo The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.5

In this paper, the design and characteristic analysis of a novel single-phase hybrid switched reluctance motor (HSRM) for the purpose of replacing the universal motor in commercial blenders are presented. The proposed motor is easy to manufacture due to its simple yet robust structure with minimized power switches and no torque dead-zone. Moreover, the proposed HSRM is able to deliver a high starting torque as a requirement for blending hard food or even ice. The stator has permanent magnets (PMs) mounted on its inner surface and the rotor has a wide pole arc and salient poles that contribute to its high starting torque profile and the elimination of the torque dead-zone. Finite element method (FEM) is used to analyze the characteristic of the proposed motor. Finally, the prototype is manufactured and its performance is verified through experiments.