INFLUENCES OF A PLASMA LAYER ON VESSEL WALL SHEAR STRESS AND WALL SHEAR STRESS GRADIENT
血浆层对血管壁剪应力和剪应力梯度的影响

Blood in small blood vessels, as a result of the tending to axis effect of blood cells, separates into two different areas, that is, a core area with blood cells and a plasma layer near wall. By applying two-phase stratified flow model in which blood in the core area is considered as Newtonian fluid and Casson fluid respectively, in the condition of the same flow rate and the same radius, influences of the plasma layer on vessel wall shear stress and shear stress gradient are researched. The results show that the existence of the plasma layer may obviously change the wall shear stress and the wall shear stress gradient. Such as, the wall shear stress and the wall shear stress gradient decreases about 10% and 20%, when the thickness of the plasma layer being only 1% and 3% of the radius of blood vessel.