【摘要】 纳米粒子的团簇普遍存在于纳米流体的沉降过程中，该文研究了TiO₂纳米粒子团簇对纳米流体辐射特性的影响。运用时域有限差分（FDTD）方法计算单个纳米粒子和团簇体的散射因子和吸收因子，根据独立散射理论计算出纳米流体的相关辐射特性参数。讨论了单团簇结构纳米流体和多团簇结构共存纳米流体的多光谱辐射特性。研究发现，在入射波长为0.40～1.00μm时，单个团簇体的吸收系数要远高于未发生团簇的单个纳米粒子，对于水基纳米流体，纳米粒子的团簇对纳米流体的辐射特性有较大影响。且在对多组分纳米流体的研究中发现，当入射波长在0.30～0.40μm时，不同比例的团簇体对多团簇结构共存纳米流体的吸收系数影响不大。另外，研究发现纳米流体的反照率与单个团簇体所包含的纳米粒子个数在较短入射波长和较长入射波长下存在反向变化趋势。更多还原

【Abstract】 Abstrcat:Nanofluids are widely used in solar photothermal conversion systems to improve the efficiency of the system. The radiation characteristics of nanoparticles are the key to influence solar energy absorption. In this paper, the effects of TiO₂ nanoparticle clusters on the radiation properties of nanofluids were studied. The scattering and absorption factors of individual nanoparticles and clusters were calculated by FDTD method, and the relevant radiation characteristic parameters of nanofluids were calculated according to the independent scattering theory. The multispectral radiation properties of single-cluster and multi-cluster nanofluids are discussed. It is found that the absorption coefficient of single clusters is much higher than that of single nanoparticles without clusters when the incident wavelength is 0.40-1.00 μm. For water-based nanofluids, the clusters of nanoparticles have a great influence on the radiation properties of the nanofluids. When the incident wavelength is 0.30-0.40 μm, it is found that the different proportion of clusters have little effect on the absorption coefficient of the multi-cluster nanofluids. In addition, it is found that the albedo of the nanofluid and the number of nanoparticles contained in a single cluster changes inversely at short and long incident wavelengths.更多还原