From molecular dynamics to lattice Boltzmann:a new approach for pore-scale modeling of multi-phase flow

Most current lattice Boltzmann （LBM） models suffer from the deficiency that their parameters have to be obtained by fitting experimental results. In this paper, we propose a new method that integrates the molecular dynamics （MD） simulation and LBM to avoid such defect. The basic idea is to first construct a molecular model based on the actual components of the rock-fluid system, then to compute the interaction force between the rock and the fluid of different densities through the MD simulation. This calculated rock-fluid interaction force, combined with the fluid-fluid force determined from the equation of state, is then used in LBM modeling. Without parameter fitting, this study presents a new systematic approach for pore-scale modeling of multi-phase flow. We have validated this ap- proach by simulating a two-phase separation process and gas-liquid-solid three-phase contact angle. Based on an actual X-ray CT image of a reservoir core, we applied our workflow to calculate the absolute permeability of the core, vapor-liquid H20 relative permeability, and capillary pressure curves.

The Higgs signatures at the CEPC CDR baseline

As a Higgs factory, the CEPC(Circular Electron-Positron Collider) project aims at precision measurements of the Higgs boson properties. A baseline detector concept, APODIS(A PFA Oriented Detector for the HIggS factory), has been proposed for the CEPC CDR(Conceptual Design Report) study. We explore the Higgs signatures for this baseline design with ■ Higgs events. The detector performance for reconstructing charged particles, photons and jets is quantified with H→μμ, γγ and jet final states, respectively. The resolutions of reconstructed Higgs boson mass are comparable for the different decay modes with jets in the final states. We also analyze the H→WW~* and ZZ* decay modes, where a clear separation between different decay cascades is observed.