Abstract In this work, random surface morphology of particles have been built to discuss the morphology’s influence on near-field radiation. The method which combines Finite Difference Time Domain (FDTD) and disperse dipole approximation (DDA) is proposed to simulate the radiative heat flux between particles. This method has been verified with the Temperature-DDA method’s results, so it can be applied in other appropriate cases. The paper uses random Gaussian distribution to constructed the rough surface and calculates radiative conductance in several deviation with different conditions such as particle shapes, material spectral properties and rotation. As results, it shows that the low deviation σ1 = r/50 (r is radius of sphere particle) has smaller influence in short spectral. When σ3 = r/10, radiative conductance reduce 10% ~ 35% in the 1–10 µm sizably, and this is caused by the particles’ irregular surface. After changing other conditions, the deviation’s influence almost keeps same standard, and the maximum radiative conductance deviation always occur in long wavelength. This work uses the real material’s properties to discuss silica particles’ radiative heat transfer, which shows that the surface morphology’s influence is finite, because radiative conductance peak also happen at about 8.5 µm wavelength.

中文翻译：

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半透明颗粒表面形貌的近场辐射传热分析

摘要 在这项工作中，建立了粒子的随机表面形态来讨论形态对近场辐射的影响。提出了时域有限差分法(FDTD)和分散偶极子近似法(DDA)相结合的方法来模拟粒子间的辐射热通量。该方法已经用温度-DDA 方法的结果进行了验证，因此它可以应用于其他适当的情况。论文采用随机高斯分布构造粗糙表面，计算粒子形状、材料光谱特性和旋转等不同条件下几种偏差下的辐射电导率。结果表明，低偏差σ1 = r/50（r为球体粒子半径）在短光谱中的影响较小。当 σ3 = r/10 时，辐射电导率在 1–10 µm 范围内大幅降低 10% ~ 35%，这是由于颗粒表面不规则造成的。改变其他条件后，偏差的影响几乎保持不变，最大辐射电导偏差总是出现在长波长处。这项工作使用真实材料的特性来讨论二氧化硅颗粒的辐射传热，这表明表面形貌的影响是有限的，因为辐射电导峰也在大约 8.5 µm 波长处发生。