{"title":"Multiphase Lagrangian Differencing Dynamics method with sharp interfaces","authors":"Manigandan Paneer , Josip Bašić , Damir Sedlar , Chong Peng","doi":"10.1016/j.enganabound.2025.106197","DOIUrl":null,"url":null,"abstract":"<div><div>Multiphase flow simulations are complex due to the intricate interactions between phases when high density and viscosity ratios are involved. These complexities often lead to challenges in capturing sharp interfaces and managing pressure jumps across phases, which can induce numerical instability. Extending the Lagrangian Differencing Dynamics (LDD) method which differs from other meshless methods by using a unique approximation scheme that ensures accurate gradients and Laplacians with second-order consistency, prioritizing consistency over traditional conservation-first approaches and also works directly on the surface meshes. This paper presents a novel Multiphase Lagrangian Differencing Dynamics (MP-LDD) with a sharp interface without density and viscosity diffusion at the interface. The method incorporates several key techniques to address the challenges: introduced a second-order consistency variable coefficient Laplacian operator for discretizing pressure and velocity equations to handle varying densities and viscosities; a systematic approach to point-cloud regularization using Position Based Dynamics (PBD) for the multiphase framework that integrates the Atwood number and increase/decrease of density to ensure a sharp and stable interface, for simulating flows with high-density ratios and mitigating unintended mixing between immiscible fluids at the interface. The Lagrangian CFL criterion is also employed for automatic time-stepping, facilitating larger time steps and accelerating simulations while maintaining numerical stability. The effectiveness of the MP-LDD approach is demonstrated through validation against various benchmark cases, including 2D Rayleigh–Taylor instability for low-density ratio, dam break & sloshing for high-density ratio & violent flows. Also, oil injection into the water scenario showcases high-density and viscosity fluids.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":"175 ","pages":"Article 106197"},"PeriodicalIF":4.2000,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Engineering Analysis with Boundary Elements","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0955799725000852","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Multiphase flow simulations are complex due to the intricate interactions between phases when high density and viscosity ratios are involved. These complexities often lead to challenges in capturing sharp interfaces and managing pressure jumps across phases, which can induce numerical instability. Extending the Lagrangian Differencing Dynamics (LDD) method which differs from other meshless methods by using a unique approximation scheme that ensures accurate gradients and Laplacians with second-order consistency, prioritizing consistency over traditional conservation-first approaches and also works directly on the surface meshes. This paper presents a novel Multiphase Lagrangian Differencing Dynamics (MP-LDD) with a sharp interface without density and viscosity diffusion at the interface. The method incorporates several key techniques to address the challenges: introduced a second-order consistency variable coefficient Laplacian operator for discretizing pressure and velocity equations to handle varying densities and viscosities; a systematic approach to point-cloud regularization using Position Based Dynamics (PBD) for the multiphase framework that integrates the Atwood number and increase/decrease of density to ensure a sharp and stable interface, for simulating flows with high-density ratios and mitigating unintended mixing between immiscible fluids at the interface. The Lagrangian CFL criterion is also employed for automatic time-stepping, facilitating larger time steps and accelerating simulations while maintaining numerical stability. The effectiveness of the MP-LDD approach is demonstrated through validation against various benchmark cases, including 2D Rayleigh–Taylor instability for low-density ratio, dam break & sloshing for high-density ratio & violent flows. Also, oil injection into the water scenario showcases high-density and viscosity fluids.
期刊介绍:
This journal is specifically dedicated to the dissemination of the latest developments of new engineering analysis techniques using boundary elements and other mesh reduction methods.
Boundary element (BEM) and mesh reduction methods (MRM) are very active areas of research with the techniques being applied to solve increasingly complex problems. The journal stresses the importance of these applications as well as their computational aspects, reliability and robustness.
The main criteria for publication will be the originality of the work being reported, its potential usefulness and applications of the methods to new fields.
In addition to regular issues, the journal publishes a series of special issues dealing with specific areas of current research.
The journal has, for many years, provided a channel of communication between academics and industrial researchers working in mesh reduction methods
Fields Covered:
• Boundary Element Methods (BEM)
• Mesh Reduction Methods (MRM)
• Meshless Methods
• Integral Equations
• Applications of BEM/MRM in Engineering
• Numerical Methods related to BEM/MRM
• Computational Techniques
• Combination of Different Methods
• Advanced Formulations.