Nek5000 기반의 마이크로 버블 유동저항감소 직접수치모사

Abstract

The microbubble generation technology in underwater vehicle is considered as one of the promising technique to reduce skin friction resistance. In the present work, microbubble dynamics were investigated in two-way coupled microbubble-laden turbulent channel flows with Nek5000 code based on the spectral element method. The Euler-Lagrange approach was adopted to predict the microbubble dynamics and to investigate the effect on flow field. The fully elastic collision model was implemented to consider the effect of wall-bubble interaction. To investigate the drag reduction effect of microbubble, turbulent flow in the channel at Reτ=135 was conducted with direct numerical simulation and a Lagrangian particle tracking approach. Three cases with different conditions in the bubble diameter and void fraction were considered.