Journal of Aerospace System Engineering (항공우주시스템공학회지)

The Society for Aerospace System Engineering (항공우주시스템공학회)
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A Numerical Analysis on Effect of Baffles in a Stirred Vessel

교반탱크에서 베플 형상의 영향에 관한 수치 해석적 연구

  • Received : 2017.09.29
  • Accepted : 2019.01.15
  • Published : 2019.02.28
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Abstract

The flow characteristics in a stirred tank are very useful in a wide variety of industrial applications. Generally, the flow pattern, power consumption and mixing time in stirred vessels depend not only on the design of the impeller, but also on the tanks' geometry and internal structure. In this study, the analysis of an unstable and unsteady complicated flow characteristics generated by the interaction between the baffle shape and impeller were performed using the ANSYS FLUENT LES Turbulence Model. The study compared the predictions of CFD with the interaction between two types of rotating impellers (axial and radial flows) and the shapes of three baffles. The results of the comparison verified that the design model showed a relatively efficient trend in the mixing flow fields and characteristics around the impeller and baffles during agitation.

교반기에서의 유동 특성은 광범위한 산업 분야에서 매우 유용하다. 일반적으로 교반되는 용기에서의 유동 패턴, 전력 소비 및 혼합 시간은 임펠러의 설계뿐만 아니라 용기 형상 및 내부 구조에 달려 있다. 본 연구에서는 베플 형상과 임펠러의 상호 작용에 의해 생성되는 불안정하고 비정상상태의 복잡한 유동 특성 분석을 ANSYS FLUENT LES 난류 모델을 사용하여 수행하였다. Axial Flow 와 Radial Flow 두 가지 타입의 회전 임펠러와 3가지 베플의 형상 사이의 상호 작용과 영향을 전산유체역학(CFD)으로 예측 비교함으로써 교반 시 임펠러와 베플 주변에서의 유동 특성과 혼합 유동장에서 상대적으로 효율적인 경향을 보이는 설계 모델을 검증할 수 있었다.

Keywords

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Fig. 1 Schematic of mixing system

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Fig. 2 Baffle shapes for CFD

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Fig. 3 Geometry of Radial flow impeller

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Fig. 4 Geometry of Axial flow impeller

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Fig. 5-1 Schematic of mixing vessel

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Fig. 5-2 Computational model on xy plane(z=0)

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Fig. 6-1 Contours of velocity magnitude with radial flow impeller and baffle (a)(b)

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Fig. 6-2 Contours of velocity magnitude with radial flow impeller and baffle (c)(d)

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Fig. 7-1 Velocity vector field with radial flow impeller and baffle (a)(b)

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Fig. 7-2 Velocity vector field with radial flowimpeller and baffle (c)(d)

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Fig. 8-1 Contours of velocity magnitude with radial flow impeller and baffle (a)(b)

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Fig. 8-2 Contours of velocity magnitude with radial flow impeller and baffle (c)(d)

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Fig. 9-1 Velocity vector field with radial flow impeller and baffle (a)(b)

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Fig. 9-2 Velocity vector field with radial flow impeller and baffle (c)(d)

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Fig. 10-1 Contours of velocity magnitude with axial flow impeller and baffle (a)(b)

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Fig. 10-2 Contours of velocity magnitude with axial flow impeller and baffle (c)(d)

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Fig. 11-1 Velocity vector field with axial flowimpeller and baffle (a)(b)

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Fig. 11-2 Velocity vector field with axial flow impeller and baffle (c)(d)

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Fig. 12-1 Contours of velocity magnitude with axial flow impeller and baffle (a)(b)

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Fig. 12-2 Contours of velocity magnitude with axial flow impeller and baffle (c)(d)

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Fig. 13-1 Velocity vector field with axial flow impeller and baffle (a)(b)

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Fig. 13-2 Velocity vector field with radial flow impeller and baffle (c)(d)

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Fig. 14 Hv with radial impeller and baffles

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Fig. 15 Hv with axial impeller and baffles

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Fig. 16 Vv with radial impeller and baffles

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Fig. 17 Vv with axial impeller and baffles

Table 1 Dimensions for mixing equipment

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