An official website of the United States government
Smoothed-particle hydrodynamics (SPH) is a mesh-free method used to simulate volumetric media in fluids, astrophysics, and solid mechanics. Visualizing these simulations is problematic because these datasets often contain millions, if not billions of particles carrying physical attributes and moving over time. Radial basis functions (RBFs) are used to model particles, and overlapping particles are interpolated to reconstruct a high-quality volumetric field; however, this interpolation process is expensive and makes interactive visualization difficult. Existing RBF interpolation schemes do not account for color-mapped attributes and are instead constrained to visualizing just the density field. To address these challenges, we exploit ray tracing cores in modern GPU architectures to accelerate scalar field reconstruction. We use a novel RBF interpolation scheme to integrate per-particle colors and densities, and leverage GPU-parallel tree construction and refitting to quickly update the tree as the simulation animates over time or when the user manipulates particle radii. We also propose a Hilbert reordering scheme to cluster particles together at the leaves of the tree to reduce tree memory consumption. Finally, we reduce the noise of volumetric shadows by adopting a spatially temporal blue noise sampling scheme. Our method can provide a more detailed and interactive view of these large, volumetric, time-series particle datasets than traditional methods, leading to new insights into these physics simulations.
more »
« less
A variable resolution SPH scheme based on independent domains coupling
Variable resolution in Smoothed Particle Hydrodynamics is essential for simulating several engineering problems characterized by different scales, to the point that this topic is listed as one of the open SPHERIC Grand Challenges. This work presents a new multi-resolution algorithm for weakly compressible Smoothed Particle Hydrodynamics (WCSPH), where an approach based on a domain-decomposition strategy is adopted. The domain is divided in an arbitrary number of different zones, which are connected only through additional Dirichlet boundary conditions enforced by buffer regions. The physical quantities of SPH particles in the buffers are computed by means of a corrected SPH interpolation over adjacent sub-domains. Specifically, a second-order kernel correction procedure is employed to ensure the proper consistency and accuracy of the interpolation. To model the mass transfer between the sub-domains, a procedure based on the evaluation of the Eulerian mass flux at the domain boundaries is applied. Particles that belong to a specific zone are created/destroyed in the buffer regions and do not interact with fluid particles that belong to a different resolution zone. One major strength of the presented multi-resolution strategy is that there is virtually no limit to the number of resolution levels that can be deployed, therefore this new model is ideal for simulating multi-scale applications. The algorithm has been implemented in the DualSPHysics opensource code [2] and optimized thanks to DualSPHysics’ parallel framework. The algorithm has been tested on a series of different cases, showing promising results for both internal and free-surface flows.
more »
« less
- Award ID(s):
- 2209793
- PAR ID:
- 10424072
- Editor(s):
- Fourtakas, G.
- Date Published:
- Journal Name:
- Proceedings of the 2023 International SPHERIC Workshop
- Page Range / eLocation ID:
- 224-231
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Inertial migration of spherical particles has been investigated extensively using experiments, theory, and computational modeling. Yet, a systematic investigation of the effect of particle shape on inertial migration is still lacking. Herein, we numerically mapped the migration dynamics of a prolate particle in a straight rectangular microchannel using smoothed particles hydrodynamics (SPH). For the first time, we identified a new logrolling behavior of a prolate ellipsoidal particle in the confined channel. Our findings are especially relevant to the applications where particle shape and alignment are used for sorting and analysis, such as shape-based enrichment of microalgae, bacteria, and chromosomes.more » « less
-
Abstract The amount of vapor in the impact-generated protolunar disk carries implications for the dynamics, devolatilization, and moderately volatile element isotope fractionation during lunar formation. The equation of state (EoS) used in simulations of the giant impact is required to calculate the vapor mass fraction (VMF) of the modeled protolunar disk. Recently, a new version of M-ANEOS (Stewart M-ANEOS) was released with an improved treatment of heat capacity and expanded experimental Hugoniot. Here, we compare this new M-ANEOS version with a previous version (N-SPH M-ANEOS) and assess the resulting differences in smoothed particle hydrodynamics (SPH) simulations. We find that Stewart M-ANEOS results in cooler disks with smaller values of VMF and in differences in disk mass that are dependent on the initial impact angle. We also assess the implications of the minimum “cutoff” density (ρc), similar to a maximum smoothing length, that is set as a fast-computing alternative to an iteratively calculated smoothing length. We find that the low particle resolution of the disk typically results in >40% of disk particles falling toρc, influencing the dynamical evolution and VMF of the disk. Our results show that the choice of EoS,ρc, and particle resolution can cause the VMF and disk mass to vary by tens of percent. Moreover, small values ofρcproduce disks that are prone to numerical instability and artificial shocks. We recommend that future giant impact SPH studies review smoothing methods and ensure the thermodynamic stability of the disk over simulated time.more » « less
-
Abstract In many electrochemical processes, the transport of charged species is governed by the Nernst–Planck equation, which includes terms for both diffusion and electrochemical migration. In this work, a multi-physics, multi-species model based on the smoothed particle hydrodynamics (SPH) method is presented to model the Nernst–Planck equation in systems with electrodeposition. Electrodeposition occurs when ions are deposited onto an electrode. These deposits create complex boundary geometries, which can be challenging for numerical methods to resolve. SPH is a particularly effective numerical method for systems with moving and deforming boundaries due to its particle nature. This paper discusses the SPH implementation of the Nernst–Planck equations with electrodeposition and verifies the model with an analytical solution and a numerical integrator. A convergence study of migration and precipitation is presented to illustrate the model’s accuracy, along with comparisons of the deposition growth front to experimental results.more » « less
-
null (Ed.)To date, large-scale fluid simulation with more details employing the Smooth Particle Hydrodynamics (SPH) method or its variants is ubiquitous in computer graphics and digital entertainment applications. Higher accuracy and faster speed are two key criteria evaluating possible improvement of the underlying algorithms within any available framework. Such requirements give rise to high-fidelity simulation with more particles and higher particle density that will unavoidably increase computational cost significantly. In this paper, we develop a new general GPGPU acceleration framework for SPH-centric simulations founded upon a novel neighbor traversal algorithm. Our novel parallel framework integrates several advanced characteristics of GPGPU architecture (e.g., shared memory and register memory). Additionally, we have designed a reasonable task assignment strategy, which makes sure that all the threads from the same CTA belong to the same cell of the grid. With this organization, big bunches of continuous neighboring data can be loaded to the shared memory of a CTA and used by all its threads. Our method has thus low global-memory bandwidth consumption. We have integrated our method into both WCSPH and PCISPH, that are two improved variants in recent years, and demonstrated its performance with several scenarios involving multiple-fluid interaction, dam break, and elastic solid. Through comprehensive tests validated in practice, our work can exhibit up to 2.18x speedup when compared with other state-of-the-art parallel frameworks.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Conference Paper:
- The DOI is not currently available.
