The development of blood-handling medical devices, such as ventricular assist devices, requires the analysis of their biocompatibility. Among other aspects, this includes , i.e., red blood cell damage. For this purpose, computational fluid dynamics (CFD) methods are employed to predict blood flow in prototypes. The most basic hemolysis models directly estimate red blood cell damage from fluid stress in the resulting flow field. More advanced models explicitly resolve cell deformation. On the downside, these models are typically written in a Lagrangian formulation, i.e., they require pathline tracking. We present a new Eulerian description of cell deformation, enabling the evaluation of the solution across the whole domain. The resulting hemolysis model can be applied to any converged CFD simulation due to one-way coupling with the fluid velocity field. We discuss the efficient numerical treatment of the model equations in a stabilized finite element context. We verify the model by comparison to the original Lagrangian formulation in selected benchmark flows. Two more complex test cases demonstrate the method’s capabilities in real-world applications. The results highlight the advantages over previous hemolysis models. In conclusion, the model holds great potential for the design process of future generations of medical devices.

中文翻译：

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用于基于应变的血液损伤建模的基于张量的形态方程的欧拉公式

血液处理医疗设备（例如心室辅助设备）的开发需要对其生物相容性进行分析。除其他方面外，这包括红细胞损伤。为此，采用计算流体动力学 (CFD) 方法来预测原型中的血流。最基本的溶血模型直接估计所产生的流场中流体应力造成的红细胞损伤。更先进的模型明确解决了细胞变形问题。不利的一面是，这些模型通常用拉格朗日公式编写，即它们需要路径跟踪。我们提出了单元变形的新欧拉描述，使得能够在整个域中评估解决方案。由于与流体速度场的单向耦合，所得溶血模型可应用于任何聚合 CFD 模拟。我们讨论在稳定的有限元环境中模型方程的有效数值处理。我们通过与所选基准流中的原始拉格朗日公式进行比较来验证模型。两个更复杂的测试用例展示了该方法在实际应用中的功能。结果凸显了相对于以前的溶血模型的优势。总之，该模型对于未来几代医疗设备的设计过程具有巨大的潜力。