论文标题
修改了多尺度辐射传热的稳定稳定离散统一气体动力学方案
Modified steady discrete unified gas kinetic scheme for multiscale radiative heat transfer
论文作者
论文摘要
在这项工作中，提出了稳定的离散统一气体动力学方案（SDUGKS）来解决稳定的辐射传递方程（RTE），这是对原始Sdugks的改进[X。 F. Zhou等人，J。Comput。物理。 423，109767（2020）]。除原始Sdugks中使用的矩形规则以外的梯形规则在跨细胞界面的能量通量重建时所采用，就像不稳定的dugks一样。通过这种方式，修改后的Sdugks的特征线长度与Dugks中的Courant-Friedrichs-Lewy（CFL）数建立了关系，这保证了修改后的Sdugks的准确性。此外，特征线长度不再受到原始sdugks中的灭绝系数的限制。结果，修改后的Sdugks比原始Sdugks更准确，更健壮，并且比Dugks在稳定的辐射问题方面更有效。此外，平滑的线性插值和范里尔限制器分别用于光滑和不连续的光学厚度的问题。进行光学厚度的几种数值测试从光学薄到厚进行了，以验证当前的方案。数值结果表明，经过修改的Sdugks可以作为研究媒体中多尺度稳定辐射传热的有效工具。
In this work, a steady discrete unified gas kinetic scheme (SDUGKS) is proposed to solve the steady radiative transfer equation (RTE), which is an improvement of the original SDUGKS [X. F. Zhou et al., J. Comput. Phys. 423, 109767 (2020)]. The trapezoidal rule other than the rectangular rule used in the original SDUGKS is adopted in the proposed method in the reconstruction of energy flux across cell interface, just as the unsteady DUGKS. By this way, the characteristic line length of the modified SDUGKS establishes a relationship with the Courant-Friedrichs-Lewy (CFL) number in the DUGKS, which guarantees the accuracy of the modified SDUGKS. Furthermore, the characteristic line length is no longer limited by the extinction coefficient like in original SDUGKS. As a result, the modified SDUGKS is more accurate and robust than original SDUGKS, and more efficient than the DUGKS for steady radiation problems. Furthermore, the smooth linear interpolation and the van Leer limiter are used for problems with smooth and discontinuous optical thicknesses, respectively. Several numerical tests with optical thickness varying from optical thin to thick are conducted to validate the present scheme. Numerical results demonstrate that the modified SDUGKS can serve as an effective tool in the study of multiscale steady radiative heat transfer in participating media.
