血液及血液替代流体流变特性实验研究

Experimental investigation of rheological properties of blood and Xanthan gum solutions as a blood analog fluid

发现和寻找一种透明的、流变特性与血液流体特性很好匹配的血液替代流体进行实验研究是非常迫切和必要的。运用美国brook公司生产的PVS Rheometer型旋流变仪对黄原胶溶液流变特性实验发现，黄原胶溶液是一种典型的剪切稀化流体，其剪切应力和剪切速率符合幂律分布；黄原胶溶液浓度越高，其剪切稀化特性越强；黄原胶溶液的表观粘度与溶液温度成反比，与溶液浓度成正比；人体血液的表观粘度介于0．4‰的黄原胶溶液（重量百分比）在温度为20℃和37℃之间的粘度值，在剪切速率介于10s^-1～500s^-1范围内，人体血液表观粘度随剪切速率的变化过程和0．4‰黄原胶溶液（温度30℃）基本重合。

Developing a shear thinning non-Newtonian fluid to substitute blood is desirable in studies of biomedicine engineering since blood is a shearing thinning non-Newtonian fluid that exhibits both viscous and elastic properties, and generally not available in large volume. The rheological properties of aqueous Xanthan gum at different concentrations and temperatures were studied in present paper. The results show that aqueous Xanthan gum is a non-Newtonian fluid which displays remarkable shear thinning behavior and can be used as a blood analog fluid. There is a power law distribution relationship between shear stress and shear rate, and the higher the solution concentration is, the more strongly it displays shear thinning behaviors. Viscosity of aqueous Xanthan gum varies with the temperature and concentration in linearity, and its value increases with the decreasing solution temperature or the increasing solution concentration. The experimental results show that, at 30℃, Xanthan gum solutions with concentration of 0.4 wt. ‰ will match human blood best in rheological properties.