Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)
- Volume 22 Issue 12
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- Pages.1647-1656
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- 1998
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- 1226-4881(pISSN)
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- 2288-5324(eISSN)
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A Study on the Drag Reduction of Shear Thinning Fluid with Vertical upward Turbulent Flow
전단박화유체의 수직상향 난류유동시 저항감소에 관한 연구
- Received : 1997.10.21
- Published : 1998.12.01
Abstract
The drag reduction is the phenomenon that occurs only when the shear stress from the wall of pipe is beyond the critical point. The drag reduction increase as the molecular weight, concentration of the polymer and Reynolds number increase, but it is limited by Virk's maximum drag reduction asymptote. Because of the strong shear force for the polymer on the turbulent flow, the molecular weight and the drag reduction do not decrease. Such mechanical degradation of the polymer occurs in all polymer solvent systems. This paper is to identify and develop high performance polymer additives for fluid transportations with the benefits of turbulent drag reduction. In addition, drag reduction in vertical flow by measuring the pressure drop and local void fraction on vertical-up flow of close system is evaluated.
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