Modeling of Fluid-Solid Two-Phase Geophysical Flows

Fluid-solid two-phase flows are frequently encountered in geophysical flow problems such as sediment transport and submarine landslides. It is still a challenge to the current experiment techniques to provide information such as detailed flow and pressure fields of each phase, which however is easily obtainable through numerical simulations using fluid-solid two-phase flow models. This chapter focuses on the Eulerian-Eulerian approach to two-phase geophysical flows. Brief derivations of the governing equations and some closure models are provided, and the numerical implementation in the finite-volume framework of OpenFOAM® is described. Two applications in sediment transport and submarine landslides are also included at the end of the chapter

Improved O(N) neighbor list method using domain decomposition and data sorting

The conventional Verlet table neighbor list algorithm is improved to reduce the number of unnecessary inter-atomic distance calculations in molecular simulations involving large amount of atoms. Both of the serial and parallelized performance of molecular dynamics simulation are evaluated using the new algorithm and compared with those using the conventional Verlet table and cell-linked list algorithm. Results show that the new algorithm significantly improved the performance of molecular dynamics simulation compared with conventional neighbor list maintaining and utilizing algorithms in serial programs as well as parallelized programs.Singapore-MIT Alliance (SMA

DEA数据标准化方法及其在方向距离函数模型中的应用

Directional distance function is the generalization of radial model in data envelopment analysis. It has the capacity of dealing with undesirable outputs, but the problem is that it has no unit-invariant measurement of efficiency, which hampers its application to empirical studies. Data normalization for data envelopment analysis is a universal solution for the problem of unit-invariance, and the efficiency keeps unchanged in radial and non-radial models after data normalization. A unit-invariant efficiency measure for directional distance function is developed based on DEA data normalization