抄録
The addition of cationic surfactants with suitable counter ion causes a remarkable drag reduction in a turbulent pipe flow. This drag-reducing technique is one of the candidates for pumping power reduction in a district heating and cooling system. Since the scale of micelles formed by surfactant additives is very small, the dynamics of rod-like micelles in a turbulent flow field can not be detected at the present stage. Also, the theoretical prediction of the movement of a rod-like micelle as a two phase turbulent flow is very difficult. The configuration of rod-like micelles and the viscoelasticity caused by the rod-like micelles are reviewed. Recent approaches to the theoretical prediction of surfactant drag reduction mechanism are also reviewed. These information reveals out the present status of drag reduction phenomenon from the stand point of multiphase flow.
