나노입자를 이용한 저항감소의 타당성검증에 대한 연구

Abstract

The objectives of this research were to study the effectiveness of polydisperse and nano-sized monodisperse particles in the turbulent boundary layer. These particles can cause the change of the characteristics into turbulent boundary layer and this research focuses on verifying the feasibility of drag reduction using polydisperse NaCl and Di-Ethyl-Hexyl-Sebacat (DEHS) particles and monodisperse NaCl nano-sized particles into micro-bubbles. In this study, we used the differential mobility analyzer (DMA) technique to generate monodisperse nano-sized particles. The goal of this work is to provide the feasibility of drag reduction using particles in the bubbles with respect to the hydrophilic/hydrophobic characteristics, poly/monodisperse nano-sized particles, the outlet position of bubbles, and flowrates. As the result of the research, polydisperse NaCl and DEHS particles reduced the total drag up to 0.31% and 0.28% respectively at the reference speed of 4m/s and the flowrate of 10LPM compared with the condition of pure bubbles. Especially, the drag reduction of nano-sized particles of around 500nm was 0.25% compared with the condition of pure bubbles.