• Title/Summary/Keyword: Inclined angle

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Mixed Convection between Inclined Parallel Plates with different Temperatures (온도차를 갖는 경사진 평행평판 내의 혼합대류 열전달)

  • Piao, R.L.;Kwon, O.B.;Bae, D.S.
    • Journal of Power System Engineering
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    • v.9 no.2
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    • pp.33-39
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    • 2005
  • Experiments are performed to study the mixed convection flow and heat transfer in an inclined parallel plates with the upper part cooled and the lower part heated uniformly. The Reynolds number ranges from $4.0{\times}10^{-3}\;to\;6.2{\times}10^{-2}$, the angle of inclination, ${\theta}$, from 0 to 45 degree from the horizontal line, and Pr of the high viscosity fluid is 909. In this paper, the PIV(Particle image velocimetry) with TLC(Thermo-sensitive liquid crystal) tracers is used for visualizing and analysis. This method allows simultaneous measurement of velocity and temperature field at a given instant of time. Quantitative data of the temperature and velocity are obtained by applying the color-image processing to a visualized image, and neural network is applied to the color-to-temperature calibration. This paper describes the methods, and presents the quantitative visualization of mixed convection. From this study, it is found that the flow pattern can be classified into three patterns which are affected by Reynolds number and the angle of inclination.

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Multiple solutions for steady state natural convection adjacent to an inclined isothermal flat plate in the region of largely upflow (상향유동 영역에서 경상등온평면에 의하여 야기된정상장태 자연대류의 다중해)

  • 유갑종;김병하;최병철
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.11 no.5
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    • pp.731-739
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    • 1987
  • This study has been performed on multiple steady-state natural convection in the upflow region induced by an inclined isothermal plate immersed in pure cold water. The newly found additional steady-state solutions are of considerable practical interest because the heat-transfer rates for a pair of solutions with determining physical parameters and boundary conditions otherwise identical are sometimes vastly different. The results are as follows: First, in the largely upflow region, two solutions exist for 0.15157

Experimental Study of the Ultrasonic Vibration Effects on CHF Occurring on Inclined Flat Surfaces (초음파 진동이 경사진 평판에서의 CHF에 미치는 영향에 대한 실험연구)

  • 정지환;김대훈;권영철
    • Journal of Energy Engineering
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    • v.12 no.2
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    • pp.139-144
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    • 2003
  • Augmentation of CHF by ultrasonic vibration in water pool is experimentally investigated under pool boiling condition. The experiments are carried out using copper coated plates and distilled water. Measurements of CHF on flat plate heated surface were made with and without ultrasonic wave and with variations in inclined angle of the surface and water subcooling. Experimental apparatus consists of a bath, power supply, test section, ultrasonic generator, and data acquisition system. The measurements show that ultrasonic wave enhances CHF and its extent is dependent upon inclination angle as well as water subcooling. The rate of increase in CHF increases with an increase in water subcooling while it decreases with an increase in inclination angle. Visual observation shows that the cause of CHF augmentation is closely related with the dynamic behavior of bubble generation and departure in acoustic field.

The Effects of the Inclination on the Performance of dead-end operating PEM Fuel Cell (고분자 연료전지의 데드엔드 운전 시 기울임에 따른 성능 변화)

  • Jeong, Jee Hoon;Kho, Back Kyun;Han, In-Su;Shin, Hyun Khil;Hur, Tae Uk;Cho, Sung Baek
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.89.2-89.2
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    • 2011
  • In automotive applicatons or water vehicles, the polymer electrolyte membrane fuel cell(PEMFC) stack is keep moving while their operation. Especially the inclination environment can take a effect to fuel cell stack perfromance, because this condition can cause a bad effect to water exhaust of fuel cell stack. In this study, a large scale stack(over 100kW power) is inclined upto 30 degree in lengthwise and crosswise using stack lift equipment. And the stack is operated in 10~100% load. No significant change has appeared in crosswise inclined condition and lenthwise low angle. But in lenthwise large angle tilting condition, the fuel cell performance has significantly decreased. And this performance decrease is aggravated in low load. An active water exhaust device is applied to the stack to prevent the performance decrease. And in lenthwise large angle tilting condition, this device cause a good effect to fuel cell stack performance.

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Numerical Analysis on Changes in Flowrate of Draft Water and Power by Changing Design Parameters of a Long-Distance Water Circulation (저층수 흡입식 광역 순환장치의 설계변수에 따른 배출량 및 소비동력 변화 특성에 대한 수치 해석 연구)

  • Song, Dong-Keun;Hong, Won-Seok;Kim, Young-Cheol;Park, Myong-Ha
    • The KSFM Journal of Fluid Machinery
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    • v.13 no.1
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    • pp.23-28
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    • 2010
  • A draft tube which has impeller to elevate bottom water and spread it over surface of lake water, induces convective circulation of lake water, a Long-Distance Circulation (LDC). Circulation of lake water make stratified water mixed and enhance DO (Dissolved Oxygen) of bottom water. Circulation rate of water is determined by draft rate of the tube, which is dependent on design parameters of the draft tube system, i. e. dimension of impeller and diffuser, inclined angle of impeller, impeller shape, and rotational speed. In this study, change in draft rate and power consumption of circulation equipment was investigated numerically with changing impeller dimension, angle and rotational speed. It was found that flowrate of draft water was increased as the dimensions of draft tube and impeller, and rotational speed and inclined angle of impeller increased. The power consumption was also elevated with increasing parameter values, and final selection of parameter values was made to satisfy target flowrates and power consumption.

Effect of thermal laser pulse in transversely isotropic Magneto-thermoelastic solid due to Time-Harmonic sources

  • Lata, Parveen;Kaur, Iqbal;Singh, Kulvinder
    • Coupled systems mechanics
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    • v.9 no.4
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    • pp.343-358
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    • 2020
  • The present research deals with the time-harmonic deformation in transversely isotropic magneto thermoelastic solid with two temperature (2T), rotation due to inclined load and laser pulse. Generalized theory of thermoelasticity has been formulated for this mathematical model. The entire thermo-elastic medium is rotating with uniform angular velocity and subjected to thermally insulated and isothermal boundaries. The inclined load is supposed to be a linear combination of a normal load and a tangential load. The Fourier transform techniques have been used to find the solution to the problem. The displacement components, stress components, and conductive temperature distribution with the horizontal distance are computed in the transformed domain and further calculated in the physical domain using numerical inversion techniques. The effect of angle of inclination of normal and tangential load for Green Lindsay Model and time-harmonic source for Lord Shulman model is depicted graphically on the resulting quantities.

Prediction of the Critical Stress for the Inclined Crack in Orthotropic Materials under Biaxial load (2축하중을 받는 직교이방성 경사균열에서 임계응력의 예측)

  • Lim, Won-Kyun;Cho, Hyung-Suk;Jeong, Woo-Kil;Lee, Ill-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.11 s.254
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    • pp.1384-1391
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    • 2006
  • The problem of an infinite anisotropic material with a crack inclined with respect to the principal material axes is analyzed. The material is subjected to uniform biaxial load along its boundary. It is assumed that the material is homogeneous, but anisotropic. By considering the effect of the horizontal load, the distribution of stresses at the crack tip is analyzed. The problem of predicting critical stress in anisotropic solids which is a subject of considerable practical importance is examined and the effect of load biaxiality is made explicitly. The present results based on the normal stress ratio theory show significant effects of biaxial load, crack inclination angle and fiber orientation on the critical stress. The analysis is performed for a wide range of the crack angles and biaxial loads.

Evaluation of the Reinforcing Effect on Shallow Foundation by Micropiles (Micropile에 의한 얕은기초의 보강효과)

  • Jeang, Jae-Young;Bae, Kyung-Tae;Park, Seong-Wan;Lee, Chong-Kyu
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.538-543
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    • 2004
  • Micropile has been widely used for reinforcing general grounds, improving slope stability and structural foundations. However, a need still exists for evaluating the effects of inclined micropiles on shallow foundations in Korea. In this paper, numerical analyses were presented to evaluate settlement characteristics on shallow foundations reinforced by micropiles and the effects of inclined micropiles under various conditions such as the installation position, installation angle, hardness(diameter), and grouting type. In addition, this paper reports trends of effectiveness and efficiency of using inclined micropiles on shallow foundations under specified conditions.

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The Effect of Compression Molding with Inclined Force for Fiber - Reinforced Thermoplastics (섬유강화 플라스틱 복합판의 압축성형에 있어서 경사하중의 영향 (AL망의 적층소재의 유동에 의하여))

  • 김만수
    • Journal of Advanced Marine Engineering and Technology
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    • v.18 no.3
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    • pp.63-67
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    • 1994
  • A main property for fiber reinforced thermoplastic composite material in compression molding is the flow of fibers. This flow is so effective a long direction of acting force that this study examined for the inclined angel of 30$^{\circ}$, 45$^{\circ}$ and 6$^{\circ}$. Below the near softing temperature of plastic, the fiber has been fractured at a point so that the fiber strength is smaller then the local hydrostatic stress in the mold. It has been found that the position of fracture is changing accrding to the incling angle. In case of the above softing temperature, the larger the inclined is, the farther the flow of fiber move. Also the plastic flow has been progresed with the cicular are type.

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Residual stress Analysis of Inclined Shot Peening Using Finite Element Method (유한요소법을 이용한 경사쇼트피닝의 잔류응력 해석)

  • Baek, Seung;Yang, Won-Ho;Seok, Chang-Sung;Ryu, Meong-Hae
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.328-333
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    • 2003
  • The purpose of this study is to analyze the impact of shot peening angle on residual stress distribution. From the residual stress analysis of perpendicular shot peening, it could be known that the residual stress in the case of high velocity is larger than low velocity, but the amount of shot size has little effect on the magnitude of compressive residual stress. The centroidal residual stress is not greatly affected by the inclined shot peening but mainly related to the unstable conditions of surface residual stress field. Therefore, this tendency may lead to reduce fatigue life of treated material.

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