During the transient phase after an impulsive spin-up from rest, the interface between two immiscible fluids in a cylindrical container changes its shape from immiscible fluids in a cylindrical container changes its shape from the horizontal initial state to the parabolical conical shape at the steady state. The transient deformation of the interface is dependent on the fluid properties as wall as rotating conditions. Two sets of fluids(engine oil-water and corn oil-glyceline)were chosen to show the effects of relative difference in viscosity on the transient interface profile development. When the fluid of lower density was of higher viscosity, the interface became concave up. This was apposite to the concave-down shape, that was usually expected in a cylinder partially-filled with water. The spin-up time scale in view of the deformation of the interface was seen to be mainly controlled by the fluid of lower viscosity. A simplified numerical modal, which was originally developed to incorporate the effect of free surface in a rotating cylinder, was extended for the case of two immiscible liquids of different densities. The computed profile of interface shape was in satisfactory agreement with the experimental results.
본 논문에서는 밀도와 점성이 서로 다른 섞임이없는 두 액체가 원통용기내에 곽차있는 상태의 정지상태에서의 스핀-엎시 밀도경계층의 시간에따른 형상을 이론적 계산과 실험적 측정에의해 연구하였다.
위의 액체가 점성이 큰 경우와 작은 경우에 대해서 연구하였으며 이때 점성비는 상당히 크다.
위의 유체가 점성이 큰 경우에 대해서는 인터페이스가 스핀-업 시간내에서 회전축 근방에서 강한 상승이 있고 아래 유체가 점성이 큰 경우에 대해서는 인테페이스가 회전축 근방에서 강한 하강이 있었다. 결국 작은 점성을 가지는 유체가 강체 회전에 도달됨으로써 모든 경우에 대해서 정상 상태인 포물선의 형상을 가진다.
