arXiv subjects

Navaneet Villodi

Publications and source records attributed to Navaneet Villodi.

3 recordsLinked to original sources

arXiv2025

Rapid Variable Resolution Particle Initialization for Complex Geometries

The accuracy of meshless methods like Smoothed Particle Hydrodynamics (SPH) is highly dependent on the quality of the particle distribution. Existing particle initialization techniques often struggle to simultaneously achieve adaptive resolution, handle intricate boundaries, and efficiently generate well-packed distributions inside and outside a boundary. This work presents a fast and robust particle initialization method that achieves these goals using standard SPH building blocks. Our approach enables simultaneous initialization of fluid and solid regions, supports arbitrary geometries, and achieves high-quality, quasi-uniform particle arrangements without complex procedures like surface bonding. Extensive results in both 2D and 3D demonstrate that the obtained particle distributions exhibit good boundary conformity, low spatial disorder, and minimal density variation, all with significantly reduced computational cost compared to existing approaches. This work paves the way for automated particle initialization to accurately model flow in and around bodies with meshless methods, particularly with SPH.

physics.comp-ph↗

arXiv2025

Adaptive Compressible Smoothed Particle Hydrodynamics

Modulating the number of particles in a region is key to accurately capturing the nuances in compressible flows with Smoothed Particle Hydrodynamics (SPH). This paper presents a volume-based adaptive refinement and derefinement procedure, with state-of-the-art features such as automatic local adaptivity and solution adaptivity applied in the context of compressible flows. A shock-aware particle shifting procedure is introduced to regularize the particle distribution while preserving the integrity of shocks. To our knowledge, this is the first demonstration of shock-based solution adaptivity and shock-aware particle shifting in the literature. A wide variety of test problems, which involve flow in and around boundaries, are employed to highlight the utility of these adaptivity features in improving the results and in making simulations faster. For instance, the adaptive resolution procedure is shown to achieve an order of magnitude increase in computational speed. We also demonstrate the effectiveness of the adaptivity procedure in resolving issues such as errors arising from the interaction with differently spaced ghost particles at boundaries, formation of spot-like structures due to particle clumping, and poorly resolved low-density regions. In essence, the adaptivity technique presented in this paper is a powerful tool for simulating compressible flows with enhanced accuracy and efficiency.

physics.flu-dyn↗

arXiv2024

Robust Solid Boundary Treatment for Compressible Smoothed Particle Hydrodynamics

The unavailability of accurate boundary treatment methods for compressible Smoothed Particle Hydrodynamics (SPH) severely limits its ability to simulate flows in and around bodies. To this end, challenges specific to compressible flows with SPH are carefully considered. Based on these, robust and widely applicable boundary treatment methods for compressible SPH are proposed. These are accompanied by a novel technique to prevent particle penetration at boundaries. The proposed methods are shown to be significantly better than other recent approaches. A wide variety of test problems, many of which are not shown to be simulated with SPH thus far, are employed to highlight the strengths and weaknesses of the proposed methods. The implementation is open source and the results are automated in the interest of reproducibility. Overall, this research contributes to the advancement of SPH as a viable alternative to mesh-based methods for compressible flow simulations.

physics.flu-dyn↗