Rethinking turbulence in blood
Rethinking turbulence in blood
复制标题
DOI：
10.3233/bir-2009-0538
复制
发表时间：
2009-01-01
期刊：
影响因子：
1.1
通讯作者：
Steinman, David A.
中科院分区：
文献类型：
--
作者：
Antiga, Luca;Steinman, David A.
通常为层流的血流可表现出高频波动，表明存在湍流，这对血管疾病的病理生理学和血液承载装置的设计具有重要意义。根据均匀流体中湍流的经典模型，这些波动可以归因于下至柯尔莫哥洛夫长度尺度的涡旋级联，对于血液中的明显湍流，据报道其为数十微米的量级。另一方面，血液主要是红细胞（RBC）的悬浮液，其大小和浓度似乎排除了这些尺度的漩涡的形成。假设耗散发生，而不是通过细胞间的相互作用介导的等离子体，在这里，我们展示了如何湍流速度波动，通常归因于湍流（雷诺）应力，可能会引起粘性剪切应力。这可能有助于解决机械性溶血理解中的根本不一致，并且它为名义上湍流下血液中有形成分实际经历的力提供了物理基础。总之，如果要获得令人满意的血液湍流定义，必须承认RBC是平等的参与者。
Blood flow, normally laminar, can exhibit high frequency fluctuations suggesting turbulence, which has important implications for the pathophysiology of vascular diseases and the design of blood-bearing devices. According to the classical model of turbulence in a homogeneous fluid, these fluctuations can be attributed to the cascade of eddies down to the Kolmogorov length scale, which, for apparent turbulence in blood, is reported to be on the order of tens of microns. On the other hand, blood is a suspension of mostly red blood cells (RBC), the size and concentration of which would seem to preclude the formation of eddies down to these scales. Assuming dissipation occurs instead via cell-cell interactions mediated by the plasma, here we show how turbulent velocity fluctuations, normally ascribed to turbulent (Reynolds) stresses, could give rise to viscous shear stresses. This may help to resolve fundamental inconsistencies in the understanding of mechanical hemolysis, and it provides a physical basis for the forces actually experienced by formed elements in the blood under nominally turbulent flow. In summary, RBC must be acknowledged as equal players if a satisfactory definition of turbulence in blood is to be achieved.