为准确获得ECMO 氧合器内血液流动细节，本文以交错排布的120 根中空纤维束构成的简化氧合器为对象，采用基于沉浸边界法(IB) 的自编程序对二维稳态血液层流进行数值模拟。结果表明，中空纤维束区域血液运动黏度变动范围在3.37∼7.04×10⁻⁶ m²/s，模拟时需要考虑血液的流变特性。通过对比IB 自编程序与商业CFD 软件Fluent 的计算结果可知，最大壁面切应力和压降的最大相对误差分别为3.38% 和2.9%，验证了IB 自编程序计算氧合器微间隙流道内血液流动的准确性。与基于多孔介质假设的一维半经验公式相比，IB 自编程序能够反映沿程粘性损失和惯性损失的变化，并可依据切应力累积值、溶血指数、血细胞停留时间三个指标对氧合器血液损伤风险进行综合评估。研究结果可为ECMO 的性能预测、临床运行参数调节提供科学依据。

In order to precisely obtain the blood flow details in ECMO oxygenators, this research takes a simplified oxygenator model consisting of 120 staggered hollow fiber bundles as the study object. The immersed boundary(IB) method code in an open-source software, foam-extend 4.0 is used to simulate the two-dimensional steady laminar flow in ECMO. The results show that in the hollow fiber region, blood kinematic viscosity changes significantly with a range from 3.37×10⁻⁶ m²/s to 7.04×10⁻⁶ m²/s. Therefore, the blood rheological properties should be considered. Comparing the results obtained from the IB method and commercial CFD software Fluent, the maximum wall shear stress and pressure drop values have maximum relative discrepancies of 3.38% and 2.9%, respectively. The results validate the accuracy of the IB method in simulating hemodynamics in micro gap passage of oxygenators. Compared with the one-dimensional porous media model, the IB method is capable of reflecting the correct proportion of the viscous and inertial loss. To further predict the risk of blood damage in the oxygenator, three indicators: stress accumulation value, hemolysis index, and blood cell residence time are calculated to assess the blood damage potential. Our results can provide a scientific basis for the performance prediction and operation adjustments in the clinical practice of ECMO.