sodium bis-(2-ethylhexyl)sulfosuccinate-water 라멜라 액정의 비뉴톤 유동곡선을 cone-plate 레오메타를 사용하여 여러 농도와 온도 조건에서 얻었다. 이러한 비뉴톤 유동곡선을 비뉴 톤 유동식에 적용하여 유동파라메타를 구하였다. 특별히 주목할 점은 액정시료의 전단속도에 대한 전단 응력은 증가와 감소에서 틱소트로피와 다일레턴시 현상을 보여 hysteresis loop를 나타내고 있다는 점이 다. sodium bis-(2-ethylhexyl)sulfosuccinate-water 라멜라 액정은 작은 전단속도에서는 약한 젤 현상 을 보이지만 응력이 한계 응력 이상에서는 비 선형 점탄성 성질을 나타낸다. 전단속도 감소에서 분산계 는 전단속도가 증가할 때 측정된 값 보다는 큰 구조변화와 전단응력을 유지하고 있다.
The rheological properties of complex materials such as colloid dispersion show complicated non-Newtonian flow phenomena when they are subjected to shear flow. These flow properties are controlled by the characteristics of flow units and the interactions among the flow segments. The rheological parameters of relaxation time (β2)0, structure factor C2 and shear modulus X2/α2 for various thixotropic flow curves was obtained by applying thixotropic equation to flow curves. The variations of rheological parameters are directly related to non-Newtonian flows, viscosities and activation energies of flow segments.
This paper presents the theoretical analysis for the flow driven by surface tension and gravity force in an inclined circular tube. The present study introduces detailed mathematical procedures for Casson viscosity model. The equations of velocity distribution and flow rate are developed to describe the displacement of a non-Newtonian fluid that continuously flew into a circular tube by surface tension. The equation of modified volumetric flow shows the complicated form of (10) due to yield stress term, and the equation of velocity distribution which includes the yield stress and inclination angle of circular tube is composed of terms of r and rc as form of (14).