血液流体设备高剪切应力内流特性与能量熵产损失  

Internal flow characteristics and energy entropy production loss in high shear stress field of blood fluid devices

作　　者：喻哲钦 王杰 王帅 许焰[3] 谭建平[3] YU Zheqin;WANG Jie;WANG Shuai;XU Yan;TAN Jianping(College of Energy and Power Engineering,Changsha University of Science and Technology,Changsha 410114,China;College of Mechanical and Electrical Engineering,Henan University of Science and Technology,Luoyang 471003,China;College of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China)

机构地区：[1]长沙理工大学能源与动力工程学院,湖南长沙410114 [2]河南科技大学机电工程学院,河南洛阳471003 [3]中南大学机电工程学院,湖南长沙410083

出　　处：《中国医学物理学杂志》2023年第10期1295-1301,共7页Chinese Journal of Medical Physics

基　　金：国家自然科学基金(52175263);湖南省自然科学基金(2022JJ40504,2021JJ30759);湖南省教育厅科学研究项目(21C0206);河南省高等学校重点科研项目计划(22A460017)。

摘　　要：血液流体设备普遍存在过度的剪切应力血液损伤与水力效率损失,这制约其实现安全、高效的长期稳定运行,探明高剪切应力下的内流特性与能量熵产损失可为设备研究与优化提供有力支持。对此,设计建立可模拟出高剪切应力流动的喷管模型,采用计算流体力学数值模拟与粒子图像测速可视化实验的研究方法,重点分析内流特性、剪切应力和能量熵产损失。研究产生高剪切应力和能量熵产损失的相关流动特征,解析熵产损失与剪切应力的关联特性。研究结果认为:流速变化梯度是产生高剪切应力的主要因素,局部高流速并不与剪切应力直接关联。高剪切应力流场中能量损失主要来源于湍流熵产,在主流段湍流熵产占总熵产的97.7%,主要分布在涡旋与流动剧烈变化的区域。流场能量熵产与剪切应力在分布状态与变化趋势上具有明显的关联一致性,抑制流场速度变化梯度可降低流动能量损失与剪切应力血液损伤。Excessive shear stress-induced blood damage and hydraulic efficiency loss are common in blood fluid devices,which limit their ability to achieve safe,efficient,and stable long-term operation.Investigating the internal flow characteristics and energy entropy production loss under high shear stress can provide support for the research and optimization of devices.A nozzle model that can simulate high shear stress flow is designed and modeled,and both computational fluid dynamics for numerical simulation and particle image velocimetry for visualization experiments are used to analyze internal flow characteristics,shear stress,and energy entropy production loss.The flow characteristics associated with high shear stress and energy entropy production loss are investigated,and the correlation between entropy production loss and shear stress is analyzed.The study concluded that velocity gradients is a major factor causing high shear stress,and that local high flow velocity is not directly associated with shear stress.The energy loss in high shear stress flow fields is mainly derived from turbulent entropy production,and the turbulent entropy production at the mainstream section accounts for 97.7%of the total entropy production,mainly distributed in vortices and the regions with drastic changes in flow.The flow field energy entropy production and shear stress have obvious correlation and consistency in the distribution state and change trend.Suppressing the flow field velocity gradient can significantly reduce the flow energy loss and shear stress-induced blood damage.

关 键 词：血液流体设备 计算流体力学 粒子图像测速 剪切应力 熵产分析 

分 类 号：R318[医药卫生—生物医学工程]