学术讲座《An HLLC-type approximate Riemann solver for two dimensional elastic-perfectly plastic model》

   应我院许晓阳教授邀请，北京应用物理与计算数学研究所沈智军研究员将于5月12日来我院访问交流，并作学术报告，欢迎各位师生参加。

时间：2023年5月12日（星期五）下午4：00

地点：临潼校区15教501-1会议室

报告题目：An HLLC-type approximate Riemann solver for two dimensional elastic-perfectly plastic model

内容摘要：In this work, we study the elastic-perfectly plastic model in two dimensional planar geometry and put forward a new HLLC-type approximate Riemann solver (HLLCN). The main feature of the new approximate Riemann solver is that it includes all stress waves, such as elastic, plastic, longitudinal and shear waves simultaneously in the presence of elastic-plastic phase transition. The analyses of the Jabocian matrix of governing equations are carried out for elasticity and plasticity separately, and the complicate order in the light of magnitude of characteristic speeds is simplified when constructing the approximate Riemann solver. The radial return mapping algorithm originally proposed by Wilkins is not only applied for the plastic correction in the discretization of the constitutive law, but also used to determine the elastic limit state in the approximate Riemann solver. A cell-centered Lagrangian method equipped with this new HLLC-type approximate Riemann solver is developed. Typical and new devised test cases are provided to demonstrate the performance of proposed method.

报告人简介：沈智军，男，北京应用物理与计算数学研究所研究员，博士生导师。1966年出生，1987年7月，获浙江大学数学系理学学士学位，2000年6月获中国工程物理研究院研究生部理学博士学位。曾担任北京计算数学学会、中国计算数学学会理事和常务理事，现为中国数学会理事。从事偏微分方程数值方法、特别是流体力学数值方法研究。部分成果目录(2022-2023)

     1. X. Wang, Z. H. dai, Z. J. Shen*, A robust and contact resolving Riemann solver for the two-dimensional ideal magnetohydrodynamics equations，J. Comput. Phys. 487 (2023) 112138.

      2. C. Zhang, L. F. Wang,  W. H. Ye,  J. F. Wu, Z. J. Shen, Igor Menshov, Mathematical modeling of transport phenomena in compressible multicomponent flows, J. Comput. Phys. 472 (2023) 111628.

     3. J. Y. Zhai, X. Li, Z. J. Shen*,A cell-centered Godunov  method based on staggered data distribution, part I: one-dimensional case，J. Comput. Math.  Accepted.

      4. J. Li ,Y. J. Gu, Y. S. Lan , Q. F. Chen , Z. G. Li , L. Liu , Z. Q. Wang , Z. J. Shen, X. R Chen, Compression of gaseous hydrogen into warm dense states up to 95 GPa using multishock compression technique, Phys. Rev. B, 107 (2023), 014309.

     5. X. Li, J. Y. Zhai, Z. J. Shen*, Elastic Hugoniot curve of one-dimensional Wilkins model with general Grüneisen-type equation of state，J. Comput. Phys. 464 (2022) 111337.  

     6. X. Wang, Z. H. dai, Z. J. Shen*, A 2D cell-centered Lagrangian scheme based on multi-state Riemann solver with exactly divergence-free magnetic fields，J. Comput. Phys. 467(2022) 111451.

     7. C. Zhang, Igor Menshov, L. F. Wang, Z. J. Shen, Diffuse interface relaxation model for two-phase compressible flows with diffusion processes，J. Comput. Phys. 466 (2022) 111356.

      8. X. Li, J. Y. Zhai, Z. J. Shen*, The complete exact Riemann solution for one-dimensional elastic-perfectly plastic  Riemann problem, Comput. Methods Appl. Mech. Engrg., 390 (2022) 114346.

      9. L. J. Wang, H. P. Guo, Z. J. Shen*, Reducing the entropy production in a Lagrangian method, Chin. J. Comput. Phys. 39(2022) 179-190.

     10. X. Li, J. Y. Zhai, Z. J. Shen*, An HLLC-type approximate Riemann solver for two-dimensional elastic-perfectly plastic model, J. Comput. Phys. 448 (2022) 110675.

     11. C. Zhang, L. F. Wang, Z. J. Shen, Z. Y. Lia, IgorMenshov, A reduced model for compressible viscous heat-conducting multicomponent flows, Computers & Fluids. 236(2022), 105311.