An overview on nonlinear porous flow in low permeability porous media
Yanzhang Huang, Zhengming Yang, Ying He, and Xuewu Wang
This paper gives an overview on nonlinear porous flow in low permeability porous media, reveals the microscopic mechanisms of flows, and clarifies properties of porous flow fluids.
Computational multiscale methods for granular materials
Xikui Li, Yuanbo Liang, Youyao Du, Ke Wan, and Qinglin Duan
The fine-scale heterogeneity of granular material is characterized by its polydisperse microstructure with randomness and no periodicity. To predict the mechanical response of the material as the microstructure evolves, it is demonstrated to develop computational multiscale methods using discrete particle assembly-Cosserat continuum modeling in micro- and macro- scales, respectively.
Two phenomena: Honji instability, and ringing of offshore structures
Honji instability and ringing of offshore structrures are two different phenomena. Honji instability occurs at a circular cylinder in transverse periodic finite motion in a water tank. It is superposed on the streaming flow induced by the cylinder's boundary layer. Its oscillation period is half of the period of the cylinder oscillation. Finite volume calculations of the filtered Navier-Stokes equations visualize the three-dimensional instability, where fluid particles transported by the circumferencial roll pairs exhibit a periodic mushroom-like pattern. Force is the same with and without the Honji instability.
Evolution of windblown sand flux and dune field — Trans-scale modeling and simulation
Windblown sand flux and dune field evolving toward the oasis have been a common ecological and environmental threat confronted by many countries. Meanwhile, it is also a kind of complex dynamical process involving multiple temporal and spatial scales which is still out of accurate description through current field observations.
Trajectory optimization and applications using high performance solar sails
Xiangyuan Zeng, Junfeng Li, Hexi Baoyin, and Shengping Gong
The high performance solar sail can enable fast missions to the outer solar system and produce exotic non-Keplerian orbits. As there is no fuel consumption, mission trajectories for solar sail spacecraft are typically optimized with respect to flight time. Several investigations focused on interstellar probe missions have been made, including optimal methods and new objective functions.
Unsteadiness in non-transferred dc arc plasma generators
Chengkang Wu and Wenxia Pan
Non-transferred dc arc plasma generators are widely used in materials processing. They are generally considered steadily-operating devises. However, unsteady phenomena do exist in them, and may cause non-ideal effects in processes which require high controllability and reproducibility. These unsteady phenomena can cause parameter fluctuations in the arc and the plasma jet, some of which have been studied in recent years. Several types and mechanisms of these phenomena have been identified. .
Mechanopathology of red blood cell diseases — Why mechanics matters
Chwee Teck Lim and Ang Li
During the onset of a disease a cell may experience alterations in both the composition and organization of its cellular and molecular structures. These alterations may eventually lead to changes in its geometrical and mechanical properties such as cell size and shape, deformability and adhesion. As such, knowing how diseased cells respond to mechanical forces can reveal ways by which they differ from healthy ones.