不同温度及曲率NaK-BASE管内Na^+和K^+迁移数值模拟

Transport numerical simulation of Na^+ and K^+in NaK-BASE tube with different temperatures and tortuosity

本文以NaK-AMTEC的BASE管内的Na^+和K^+迁移为研究对象,建立了NaK-BASE管显微结构的分形模型,采用微观Poisson-Nernst-Planck多离子运移模型模拟了Na^+和K^+在BASE管中的迁移,考察了不同温度下NaK-BASE管内离子的迁移过程。研究结果表明,NaK-BASE管内的阳离子迁移浓度和表面电荷密度与BASE管的温度直接相关;温度的升高会使BASE管内阳离子浓度峰值有所减小,可通过增加BASE管曲率来提高该峰值。BASE管内的表面电荷密度随着温度的升高逐渐增大,且不同温度表面电荷密度之差随着曲率的增加逐渐增大。

We established a fractal model for the microstructure of NaK-BASE tube with the transport of Na＋ and K＋ in NaK-BASE tube as a subject. We simulated the transport of Na＋ and K＋ in NaK-BASE tube with Poisson-Nernst-Planck multi-ions transport model. We also investigated ion transport process in NaK-BASE tube with different temperatures. Results show that cation transport concentration and surface charge density of Na＋ and K＋ have direct relationship with the temperature of NaK-BASE tube. Peak value of cation concentration in NaK-BASE tube will decrease with the increase of BASE tube temperature. Peak value of Na＋ and K＋ can be enhanced by the increase of NaK-BASE tube tortuosity. Moreover, surface charge density of Na＋ and K＋ in BASE tube gradually increases with the increase of temperature. Discrepancy of surface charge density gradually increases with the increase of tortuosity.