• Title/Summary/Keyword: fluid flow velocity

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Numerical and Experimental Analysis of Tunnel Flow Induced by Jet Fan (제트홴에 의해 형성되는 터널내 유동의 실험 및 수치적 해석)

  • Kim, Jung-Yup;Yang, Sang-Ho
    • The KSFM Journal of Fluid Machinery
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    • v.13 no.3
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    • pp.59-64
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    • 2010
  • To analyze the three-dimensional flow in tunnel caused by operation of jet fan, both experimental and computational studies have been conducted. The experimental analysis of tunnel flow induced by jet fan is conducted on a real-scale apparatus with jet fan and tunnel, and air velocity at the monitoring points is measured for variation of fan's RPM. The three-dimensional numerical analysis including tunnel and jet fan is carried out for the same geometric configuration as the experimental analysis. The experimental and computational results are compared to examine the applicability of the numerical method.

Mixed Convection in a Horizontal Annulus with a Rotating Cylinder (하나의 실린더가 회전하는 수평 환형 공간에서의 혼합 대류)

  • Yoo Joo-Sik;Ha Dae-Hong
    • Journal of computational fluids engineering
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    • v.6 no.3
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    • pp.1-9
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    • 2001
  • Mixed convection in a horizontal annulus is considered, and the effect of a forced flow on the natural convective flow is investigated. The inner cylinder is hotter than the outer cylinder, and the outer cylinder is rotating with constant angular velocity with its axis at the center of the annulus. The unsteady streamfunction-vorticity equation is solved with a finite difference method. For the fluid with Pr=0.7, there appear flows with two eddies, one eddy, or no eddy according the Rayleigh and Reynolds numbers. The rotation of the outer cylinder reduces the heat transfer rate at the wall of the annulus. The oscillatory multicellular flow of a low Prandtl number fluid with Pr=0.01 can be effectively suppressed by the forced flow.

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Characteristics of Fluid Flow in a Solid Particle Circulating Fluidized Heat Exchanger (고체입자 순환유동층 열교환기의 유동특성)

  • Lee, B.C.;Ahn, S.W.;Kim, W.C.;Lee, Y.P.
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.705-710
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    • 2001
  • The commercial viability of heat exchanger is mainly dependent on their long-term fouling characteristics because the fouling increases the pressure loss and degrades the thermal performance of a heat exchanger. An experimental study was performed to investigate the characteristics of fluid flow in a fluidized bed heat exchanger with circulating various solid particles. The present work showed that the drag force coefficients of particles in the internal flow were higher than in the external flow, in addition, they were lower with the shapes of particles being closer to the spherical geometries.

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Rotating Flows in a Circular Cylinder with Unstable Stratification (불안정 성층화를 가진 원통형 용기 내의 회전유동에 관한 연구)

  • Kim, Jae-Won
    • Journal of computational fluids engineering
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    • v.3 no.2
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    • pp.27-38
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    • 1998
  • Rotating flow of a stratified fluid contained in a circular cylinder with unstable temperature gradient imposed on the side wall of it has been numerically studied. The temperatures at the endwall disks are constant. The top disk of the container is coider than that of the bottob disk, as much as the temperature difference n${\Delta}$T, (0${\leq}$n${\leq}$3). Flows in the vessel are driven by an impulsive rotation of the hot bottom disk with respect to the central axis of the cylinder. Flow details have been acquired. For this flow, the principal balance in the interior core is characterized by a relationship between the radial temperature gradient and the vertical shear in the azimuthal velocity. As the buoyancy effect becomes appreciable, larger portions of the meridional fluid transport are long-circuit from the bottom disk to the interior region via the side wall.

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A Characteristics of a Secondary flow in a Corner Section of Square Duct (정사각덕트의 코너부에서 이차유동 특성)

  • Joung, J.M.;Kim, J.H.;Yoo, Y.T.
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.753-758
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    • 2000
  • Heat engine and fluid machinery in the plant have to linked with various ducts network and the corresponding design have to be concerned about effectiveness and stability of system of plant. To optimum control and design system concerning stability, economization, operating effectiveness we have to exact analysis flow properties of a duct applying to fluid machinery, heat exchanger, cooling machine, air conditioning equipment. therefore, it is necessary to research the duct, heat transfer equipment, for increasing overall effectiveness of air conditioning system by suggesting basic data of the duct resulting from organic research. So we can contribute to technical development of the duct. In case of speeding up the flow rate of the duct, lots of wave velocity components are occurred the value of boundary layer resulting from developing the boundary layer at both walls of duct.

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Aerodynamic Design of the Axial Fan (축류 송풍기의 공력학적 설계)

  • Sohn, Sang-Bum;Joo, Won-Gu;Cho, Kang-Rae;Nam, Hyung-Baik;Yoon, In-Kyu;Nam, Leem-Woo
    • The KSFM Journal of Fluid Machinery
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    • v.2 no.1 s.2
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    • pp.22-28
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    • 1999
  • In this study, a preliminary design method of the axial fan was systematically established based on the two-dimensional cascade theory. Flow deviation, lift coefficient, distribution of velocity and pressure coefficient on blade surfaces were predicted by an inviscid flow theory of Martensen method, which was also applied to select an airfoil for required performance in the present design process. The aerodynamic performance of designed blades can be predicted quickly and reasonably by using the through-flow calculation method in the preliminary design process. It would be recommendable to adopt three-dimensional viscous flow calculation at the final design refinement stage.

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Numerical Simulation of Flow and Dross Particle Transfer in a 55% Al-Zn Pot

  • Kim, Hwang Suk;Kim, Jong Gi;Yoon, Seung Chae;Im, Hee Joong;Moon, Man Been
    • Corrosion Science and Technology
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    • v.11 no.3
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    • pp.71-76
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    • 2012
  • Computational fluid dynamics (CFD) is nowadays a powerful and reliable tool for simulating different flow processes and temperature. CFD is used to analyze the various pot geometries and operative variables in 55% Al-Zn pot of CGL. In this research, different strip velocities were assumed and then shown the flow pattern in the pot that was similar in the different strip velocities. Temperature distribution in the pot depended on inductors and inlet strip temperature at the steady condition. Generation of dross particles and transport models were considered to describe dross particles evolution inside the pot. In order to observe dross influence by scrap location, dross particles were generated upon the sink roll. Floating time of dross particles is different by scraper locations above the sink roll.

Turbulent Particle Dispersion Effects on Electrostatic Precipitation (전기집진에서의 난류 입자 이산)

  • Choe, Beom-Seok;Fletcher C.A.J
    • 연구논문집
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    • s.28
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    • pp.39-47
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    • 1998
  • Industrial electrostatic precipitation is a very complex process, which involves multiple-way interaction between the electric field, the fluid flow, and the particulate motion. This paper describes a strongly coupled calculation procedure for the rigorous computation of particle dynamics during electrostatic precipitation. The turbulent gas flow and the particle motion under electrostatic forces are calculated by using the commercial computational fluid dynamics (CFD) package FLUENT linked to a finite-volume solver for the electric field and ion charge. Particle charge is determined from both local electrical conditions and the cell residence time which the particle has experienced through its path. Particle charge density and the particle velocity are averaged in a control volume to use Lagrangian information of the particle motion in calculating the gas and electric fields. The turbulent particulate transport and the effects of particulate space charge on the electrical current flow are investigated. The calculated results for poly-dispersed particles are compared with those for mono-dispersed particles, and significant differences are demonstrated.

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Boundary layer analysis of persistent moving horizontal needle in Blasius and Sakiadis magnetohydrodynamic radiative nanofluid flows

  • Krishna, Penem Mohan;Sharma, Ram Prakash;Sandeep, Naramgari
    • Nuclear Engineering and Technology
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    • v.49 no.8
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    • pp.1654-1659
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    • 2017
  • The boundary layer of a two-dimensional forced convective flow along a persistent moving horizontal needle in an electrically conducting magnetohydrodynamic dissipative nanofluid was numerically investigated. The energy equation was constructed with Joule heating, viscous dissipation, uneven heat source/sink, and thermal radiation effects. We analyzed the boundary layer behavior of a continuously moving needle in Blasius (moving fluid) and Sakiadis (quiescent fluid) flows. We considered Cu nanoparticles embedded in methanol. The reduced system of governing Partial differential equations (PDEs) was solved by employing the Runge-Kutta-based shooting process. Computational outcomes of the rate of heat transfer and friction factors were tabulated and discussed. Velocity and temperature descriptions were examined with the assistance of graphical illustrations. Increasing the needle size did not have a significant influence on the Blasius flow. The heat transfer rate in the Sakiadis flow was high compared with that in the Blasius flow.

Flow Analysis of the Rotating Sludge Suction Collector by Numerical Simulation (수치시뮬레이션을 이용한 흡입식 슬러지 수집기의 유동해석)

  • Suh, Sang-Ho;Roh, Hyung-Woon;Byun, Jong-Youn
    • The KSFM Journal of Fluid Machinery
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    • v.9 no.5 s.38
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    • pp.22-27
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    • 2006
  • Sedimentation phenomenon of suspended solids occurs by the gravitational force. Pollution particles are separated from slowly flowing waste water in clarifier. Recently, the sludge suction collector is Preferred rather than the scraper type sludge collector due to the enhancement of the clarifier efficiency. The sludge suction collector is usually operated by the user's experiences without any scientific and/or technical consideration. To evaluate the performance of sludge suction collector, the three dimensional numerical simulation was conducted by the finite volume method. To analyze the performance, the velocity vectors and the suction flow rates of the orifices were investigated. The result showed that each suction flow rate through out the collector was equivalent in the sludge suction collector and the efficiency of suction collector was good to remove high concentrated sludge in clarifier.