Computational fluid dynamics simulation showing LBM, CLE, and SPH methods.

Fluid Dynamics Face-Off: Benchmarking the Best Computational Methods

Rhea Morgan in Tech & Innovation September 2025 • 4 min read.

"Lattice-Boltzmann, Coupled Lagrangian-Eulerian, and Smoothed Particle Hydrodynamics go head-to-head in resolving shear-driven flow fields."

The interplay between fluids and structures—known as fluid-structure interaction (FSI)—is critical in numerous engineering applications, from designing aircraft engines that can safely ingest soft bodies to understanding how blood flows through arteries affected by plaque. Accurately modeling FSI requires capturing how fluids influence structures and vice versa; neglecting either aspect can lead to flawed predictions and designs.

Currently, two main strategies tackle FSI: monolithic approaches, where fluid and structural equations are solved simultaneously, and partitioned approaches, which couple individual fluid and structural solvers. Monolithic methods tend to be more stable, while partitioned methods can be more computationally efficient. This article compares three methods: two monolithic (Coupled Lagrangian-Eulerian (CLE) and Smoothed Particle Hydrodynamics (SPH)) and one partitioned (lattice-Boltzmann methods (LBM)).

CLE and SPH have proven their ability to model significant structural deformation and domain separation. LBM has demonstrated its ability as an explicit fluid solver. This study aims to validate fluid domain responses for future FSI applications. By comparing and validating fluid modeling capabilities of monolithic and partitioned methods, this work sets the stage for more complex FSI simulations.

The Methodology Throwdown

Computational fluid dynamics simulation showing LBM, CLE, and SPH methods.

This study investigates the accuracy and efficiency of three computational fluid dynamics (CFD) methods: Lattice-Boltzmann Method (LBM), Coupled Lagrangian-Eulerian (CLE), and Smoothed Particle Hydrodynamics (SPH). These methods are evaluated by simulating a lid-driven cavity flow, a classical problem in fluid dynamics. The results are compared to an implicit Navier-Stokes solution and established literature to determine the strengths and weaknesses of each approach.

The lid-driven cavity problem involves a square cavity with three stationary walls and one moving wall (the lid) that drives the fluid motion. This setup creates a shear-driven flow, characterized by the formation of vortices. The simplicity of the geometry belies the complexity of the flow field, making it an ideal benchmark for CFD methods. The study focuses on low Reynolds numbers (100-3200) to avoid the complexities of turbulence modeling.

Navier-Stokes (Baseline): Solved using ANSYS FLUENT to provide a steady-state, incompressible baseline solution.
Lattice-Boltzmann Method (LBM): A partitioned method using a simplified, Boolean gas particle motion on a lattice structure.
Coupled Lagrangian-Eulerian (CLE): A monolithic method using an FE formulation designed for FSI and metal forming.
Smoothed Particle Hydrodynamics (SPH): A monolithic method that discretizes the fluid domain using a set of volumeless particles.

A grid resolution study is performed to ensure that the solutions are independent of the mesh size. The computational cost, accuracy, and ability to capture key flow features, such as vortices, are assessed for each method. The study also examines how each method handles boundary conditions and potential numerical instabilities.

The Verdict

The study concludes that LBM and CLE show the most promise for modeling complex fluid flows, demonstrating good accuracy and computational efficiency. SPH, while versatile, requires further development to improve its accuracy and stability in commercial implementations. These findings provide valuable insights for researchers and engineers selecting CFD methods for FSI simulations and other fluid dynamics applications.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1115/1.4036590, Alternate LINK

Title: Benchmarking Of Computational Fluid Methodologies In Resolving Shear-Driven Flow Fields

Subject: Mechanical Engineering

Journal: Journal of Fluids Engineering

Publisher: ASME International

Authors: Brandon Horton, Yangkun Song, Jeffrey Feaster, Javid Bayandor

Published: 2017-08-11

Everything You Need To Know

How does the Lattice-Boltzmann Method (LBM) function, and what are its specific advantages and limitations in the context of fluid dynamics simulations?

The Lattice-Boltzmann Method (LBM) stands out due to its efficiency as an explicit fluid solver and its suitability for fluid-structure interaction (FSI) applications. It operates as a partitioned method, using a simplified, Boolean gas particle motion on a lattice structure. While the study validates its fluid domain responses, it's important to note that LBM's performance can be influenced by the complexity of boundary conditions and the potential for numerical instabilities, areas that require careful consideration in practical applications.

What distinguishes Coupled Lagrangian-Eulerian (CLE) and Smoothed Particle Hydrodynamics (SPH) as monolithic methods, and how does this categorization influence their performance in modeling fluid-structure interactions?

Coupled Lagrangian-Eulerian (CLE) and Smoothed Particle Hydrodynamics (SPH) are categorized as monolithic methods. This means they solve fluid and structural equations simultaneously, which can lead to greater stability in certain simulations. CLE is based on a Finite Element (FE) formulation and is designed specifically for fluid-structure interaction (FSI) and metal forming simulations, making it well-suited for scenarios involving significant structural deformation. SPH, on the other hand, discretizes the fluid domain using a set of volumeless particles, offering versatility but potentially requiring further development to enhance its accuracy and stability in commercial applications.

What is the significance of the lid-driven cavity flow problem, and why was it chosen as a benchmark for evaluating Lattice-Boltzmann Method (LBM), Coupled Lagrangian-Eulerian (CLE), and Smoothed Particle Hydrodynamics (SPH)?

The lid-driven cavity flow is used to compare the accuracy and efficiency of Lattice-Boltzmann Method (LBM), Coupled Lagrangian-Eulerian (CLE), and Smoothed Particle Hydrodynamics (SPH). This problem involves a square cavity with three stationary walls and one moving wall, which creates a shear-driven flow and vortices. This setup provides a controlled environment to assess how well each method captures key flow features and handles boundary conditions.

What are the main differences between monolithic and partitioned approaches in fluid-structure interaction (FSI) simulations, and how do methods like Coupled Lagrangian-Eulerian (CLE) and Lattice-Boltzmann Method (LBM) exemplify these strategies?

In fluid-structure interaction (FSI), monolithic approaches, like Coupled Lagrangian-Eulerian (CLE) and Smoothed Particle Hydrodynamics (SPH), solve fluid and structural equations simultaneously, generally leading to more stable solutions. Partitioned approaches, such as Lattice-Boltzmann Method (LBM), couple individual fluid and structural solvers, potentially offering computational efficiency. The choice between them depends on the specific application, with monolithic methods favored where stability is paramount and partitioned methods where computational speed is critical.

Based on the study's findings, what are the comparative strengths and weaknesses of Lattice-Boltzmann Method (LBM), Coupled Lagrangian-Eulerian (CLE), and Smoothed Particle Hydrodynamics (SPH) for modeling complex fluid flows and fluid-structure interaction (FSI) phenomena?

The study indicates that both Lattice-Boltzmann Method (LBM) and Coupled Lagrangian-Eulerian (CLE) exhibit significant promise for modeling complex fluid flows, showcasing a combination of accuracy and computational efficiency. Smoothed Particle Hydrodynamics (SPH), although noted for its versatility, needs further refinement to improve its accuracy and stability within commercial implementations. These results underscore the importance of method selection based on the specific demands of fluid dynamics and fluid-structure interaction (FSI) simulations, guiding researchers and engineers towards optimal choices for their projects.