An improved SPH model for multiphase flows with large density ratios |
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| Authors: | GX Zhu L Zou Z Chen AM Wang MB Liu |
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| Affiliation: | 1. State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian, China;2. School of Naval Architecture, Dalian University of Technology, Dalian, China;3. Department of Mechanical Engineering, National University of Singapore, Singapore, Singapore;4. BIC‐ESAT, College of Engineering, Peking University, Beijing, China;5. State Key Laboratory for Turbulence and Complex Systems, Peking University, Beijing, China |
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| Abstract: | This paper presents a new smoothed particle hydrodynamics (SPH) model for simulating multiphase fluid flows with large density ratios. The new SPH model consists of an improved discretization scheme, an enhanced multiphase interface treatment algorithm, and a coupled dynamic boundary treatment technique. The presented SPH discretization scheme is developed from Taylor series analysis with kernel normalization and kernel gradient correction and is then used to discretize the Navier‐Stokes equation to obtain improved SPH equations of motion for multiphase fluid flows. The multiphase interface treatment algorithm involves treating neighboring particles from different phases as virtual particles with specially updated density to maintain pressure consistency and a repulsive interface force between neighboring interface particles into the pressure gradient to keep sharp interface. The coupled dynamic boundary treatment technique includes a soft repulsive force between approaching fluid and solid particles while the information of virtual particles are approximated using the improved SPH discretization scheme. The presented SPH model is applied to 3 typical multiphase flow problems including dam breaking, Rayleigh‐Taylor instability, and air bubble rising in water. It is demonstrated that inherent multiphase flow physics can be well captured while the dynamic evolution of the complex multiphase interfaces is sharp with consistent pressure across the interfaces. |
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| Keywords: | interface large density ratios multiphase flows smoothed particle hydrodynamics |
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