The multi-phase particle swarm optimization (MPPSO) technique is applied to retrieve the particle size distribution (PSD) under dependent model.Based on the Mie theory and the Lambert-Beer theory,three PSDs,i.e.,the Rosin-Rammer (R-R) distribution,the normal distribution,and the logarithmic normal distribution,are estimated by MPPSO algorithm.The results confirm the potential of the proposed approach and show its effectiveness.It may provide a new technique to improve the accuracy and reliability of the PSD inverse calculation.
A finite element model is developed to simulate the radiative transfer in 2D and 3D complex-geome-tric enclosure filled with absorbing and scattering media. This model is based on the discrete ordinates method and finite element theory. The finite element formulations and detailed steps of numerical calculation are given. The discrepancy of the results produced by different space and solid angle discretization is also investigated and compared. The effect of the six-node quadric element on the accuracy is analyzed by a 2D rectangular enclosure. These results indicate that the present model can simulate radiative transfer in multidimensional complex-geometric enclosure with participating media effectively and accurately.
基于传统热流法,提出一种圆柱坐标系下的源项六流模型(Source Six Flux,SSF),可快速准确地计算参与性介质内任意方向的出射辐射强度.详细介绍SSF模型的基本原理和求解步骤,以圆柱形吸收、散射、发射性介质为例,模拟其沿任意方向的出射辐射强度,并与反向蒙特卡罗法(Backward Monte Carlo,BMC)和二流法(Two Flux Method,TFM)的计算结果进行比较.结果表明,SSF法与BMC法的计算结果吻合较好,计算精度均高于TFM法,但SSF法的计算效率明显优于BMC法.因此,SSF模型是一种适用于计算任意方向辐射强度问题的高效数值模型.
