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Pilot규모에서 계면활성제용액의 장기 마찰저항감소에 관한 연구
박성룡,이상남,문승현,윤형기,Park, S.R.,Lee, S.N.,Moon, S.H.,Yoon, H.K. 대한설비공학회 1997 설비공학 논문집 Vol.9 No.3
The long term drag reduction characteristics of Habon-G solution were investigated in the KIER pilot-scaled district heating simulation system. Test runs were implemented for 30 days without interruption. Pressure drop, flow rate and power consumption of surfactant (Habon-G) solution were regularly observed and compared with those of plain water. The experimental results suggest that the surfactant can be effectively applied to the DH transmission system for considerably long period wthout significant loss of its drag reduction capability even though the concentration of the additive may gradually decrease in the first stage of the experiment because of absorption.
난류 유동일때 관과 channel에서 고분자와 계면활성제에 의한 마찰저항 감소에 관한 연구
박성룡,Park, S.-R. 대한설비공학회 1995 설비공학 논문집 Vol.7 No.3
The drag reduction phenomenon with an additives of surfactant(STAC, stearlytrimethyl ammonium chloride) and polymer(PEO, polyethlene oxide) was investigated in fully developed turbulent pipe and channel flows at various low Reynolds numbers as well as very low additives concentration. A maximum of 70% drag reduction compared with plain water flow was found. This maximum drag reduction percentage obtained with surfactant solution was slightly higher than that of the Virk's asymptote in polymer solution.
난류 관유동에서 마찰저항감소 첨가제에 대한 펌프와 온도의 영향
박성룡,서항석,윤형기,Park, S.R.,Suh, H.S.,Yoon, H.K. 대한설비공학회 1996 설비공학 논문집 Vol.8 No.3
The effects of pump and temperature on drag reducing characteristics were investigated with a polymer(PAAM : Polyacrylamide) and three kinds of surfactants(CTAC, STAC, Habon-G) in fully developed turbulent pipe flows with various experimental parameters such as additive concentration(30~500ppm), pipe diameter(4.65mm, 10.85mm), Reynolds number($4{\times}10^4{\sim}10^5$) and working fluid temperature($20{\sim}80^{\circ}C$). The pump effect on PAAM was severe such that the drag reduction rates obtained with pump were decreased upto 30% as compared with those obtained with compressed air in 4.65mm test section. The temperature effect on PAAM was noticeably considerable, that is, the higher temperaute, the less drag reduction rate. On the other hand, no significant pump effect on the surfactants was observed. The drag reducing effectiveness of CTAC was totally lost in the temperature ragne of 60 to $80^{\circ}C$, whereas STAC and Habon-G kept their distinct drag reducing capability at a temperature of $80^{\circ}C$. This study clearly elucidated that for DHC application of drag reducing additives, the pump and temperature effects as well as additive concentration and pipe diameter should be carefully taken into consideration.
박성룡,윤형기,Park, S.R.,Yoon, H.K. 대한설비공학회 1996 설비공학 논문집 Vol.8 No.4
A 2D-LDV system was employed to investigate the flow field characteristics in fully developed drag reducing turbulent channel flows. The additive used in this study was Habon-G which showed splendid drag reduction effect and minimum mechanical degradation trend in the closed flow circulation loop. In order to have better understanding of the drag reduction mechanism, the instantaneous velocities were carefully measured under various experimental conditions and the flow characteristics including time-averaged velocity, turbulent intensity and Reynolds shear stresses were carefully assessed. The time-averaged velocity profiles of surfactant flows showed more parabolic shape(typically shown in a laminar flow) together with significant suppression of turbulent production, yielding the shear induced micelle structure orienting in the flow direction due to its isotropic characteristics. Especially it was observed that the maximum intensity for drag reducing flows was shifted away from the wall and that the streamwise and normal turbulent intensities were strongly altered. This phenomenon strongly suggests that the viscous sublayer becomes thicker with addition of surfactant. Turbulent momentum transport was drastically suppressed across the whole drag reducing channel flow.