PowerFLOW LBM CFD Software For Aerodynamics, Aeroacoustics And Thermal Management

PowerFLOW is an inherently transient Lattice Boltzmann-based CFD software by Dassault Systemes that performs fluid flow simulations that accurately predict real world conditions. The PowerFLOW suite facilitates high-fidelity, scale-resolving simulations, empowering engineers and designers to assess product performance early in the design process through digital prototyping, ultimately conserving time, resources, and budget. PowerFLOW is widely used in the industry today to solve the most complex problems in Aerospace, Defense, Transportation, and Mobility sectors.

SIMULIA PowerFLOW

The PowerFLOW suite offers some unique features and capabilities that lead to key benefits towards simulating and predicting real world fluid flow scenarios.

  • High fidelity scale resolving simulations: Accurate results across most fluid flow regimes ranging from subsonic to transonic and laminar to turbulent. The Very Large Eddy Scale (VLES) turbulence modeling approach accurately resolves and models fine scale turbulence in the flow, leading to accurate aerodynamics and aeroacoustics predictions for the most complex of flows.
  • No volume & boundary layer meshing: Automated domain discretization without the need for manual volume meshing and boundary layer meshing, and turbulence modeling with accurate wall treatment. This makes the CFD model setup and meshing straightforward and less cumbersome as compared to traditional Navier-Stokes solvers.
  • Highly parallelized & scalable solution: PowerFLOW can be run on massively parallel High Performance Computing (HPC) systems using a large number of compute cores.
  • GPU acceleration: CFD simulations can be sped up further as PowerFLOW simulations can be run on GPUs.
  • Coupled physics – fluids, thermal, acoustic: PowerFLOW can be integrated with with PowerTHERM for thermal analysis, as well as PowerACOUSTICS for accurate aeroacoustic noise predictions.
  • Complex physical modeling: PowerFLOW can simulate true rotating geometries using Local Reference Frame (LRF), support particle modeling, heat exchangers, porous media, and thermal and acoustic predictions, making it a powerful tool to simulate various types of coupled physics for an engineering system or product.

Where PowerFLOW Excels

PowerFLOW can be utilized for all manner of fluids problems, but there are a number of applications for which it truly excels. Aerodynamics, aeroacoustics and thermal management are three of those applications:

PowerFLOW For Aerodynamics

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PowerFLOW is a game-changer for aerodynamic simulations, offering significant speed and efficiency advantages over traditional Navier-Stokes (NS) solvers. What typically takes 28 days in NS can be completed in just 3 days with PowerFLOW, enabling faster design iterations and reducing development timelines. Its Lattice Boltzmann-based approach delivers high-fidelity, transient results that accurately capture flow separation, wake dynamics, and other critical aerodynamic phenomena. For industries like aerospace and automotive, where optimizing performance and fuel efficiency is crucial, PowerFLOW provides the tools to rapidly evaluate and refine designs, bringing products to market faster.

PowerFLOW For Aeroacoustics

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When it comes to aeroacoustics, PowerFLOW truly shines, thanks to its inherently transient Lattice Boltzmann Method (LBM) framework. Unlike traditional Navier-Stokes (NS) solvers, which often require post-processing or additional models to estimate acoustic wave propagation, LBM calculates pressure fluctuations directly during the simulation. This direct approach provides a more seamless and accurate prediction of acoustic wave generation and propagation. It is especially effective in capturing unsteady flow phenomena, such as vortex shedding and turbulence, which are key contributors to noise.

SIMULIA PowerFLOW

For applications like aircraft, EVTOLs, and automotive cabins, PowerFLOW enables precise identification of noise sources and supports the development of effective noise mitigation strategies. Additionally, its low numerical dissipation ensures that acoustic waves are preserved over long distances, making it ideal for simulating the complex interactions between flow and sound in real-world scenarios. By leveraging PowerFLOW, engineers can accelerate the development process, meet stringent noise regulations, and enhance overall system performance, particularly in noise-critical designs.

PowerFLOW For Thermal Management

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PowerFLOW’s multiphysics capabilities make it uniquely suited for thermal management simulations. By coupling fluid flow with thermal analysis through tools like PowerTHERM and PowerCOOL, PowerFLOW can accurately predict heat transfer from conduction, convection, and radiation across complex systems. For applications like EVTOLs, where managing heat across propulsion systems and electronic components is critical, PowerFLOW simplifies the process of optimizing thermal performance while reducing simulation setup time. Its ability to seamlessly integrate thermal and flow physics ensures faster, more comprehensive evaluations of vehicle designs, making it an invaluable asset for engineers tackling modern thermal challenges.

How Does The Lattice Boltzmann Method Work?

The Lattice Boltzmann Method (LBM) is the backbone of the PowerFLOW CFD software. This is an alternative method to mathematically describe fluid flow behavior and is becoming increasingly popular in modern CFD codes. While the Navier-Stokes equations describe fluid flow behavior at the macroscopic scale under the assumption of continuum, LBM is based on the discrete approximation of kinetic theory at the mesoscopic scale. The mesoscopic scale lies between the microscopic (atomic or molecular level) and the macroscopic scale (scales large enough that they can be observed by the naked eye, and fluid properties can be described by bulk quantities).

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In LBM, the fluid domain is represented by a set of discrete lattices, and fluid properties are calculated on these discrete lattices by means of a probability distribution function. Here, a lattice is a structured grid in space, where each point on this grid, referred to as a lattice site or node, acts as a discrete location where fluid properties are computed and updated. An example of a 2D lattice is shown below, commonly referred to as the D2Q9 lattice model (2 dimensional, with 9 lattice sites).

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Figure 1: A Lattice Structure in 2D: D2Q9

Based on this lattice structure, the solution is obtained in a 2-step process:

  1. Collision: Particles at each lattice node collide with each other, imparting different particle velocities to the particles, while conserving mass and momentum.
  2. Propagation: After collisions, the particles propagate to neighboring nodes, based on the new/updated velocities, and the new position of the fluid particles is calculated.

This collision and propagation process can be represented by the following equation:

SIMULIA PowerFLOW

where,

fi is the discrete probability distribution function of the particle position at position i, where i = (0, 1, …, m – 1), and m is the number of lattice nodes on a lattice (m = 9 on a DQ29 lattice shown above),

c is the lattice speed,

τ is the relaxation parameter.

The collision process is represented on the left side of the equation, whereas the right side represents the propagation process. These two processes form the backbone of LBM and describe how fluid particles move in a flow through the lattice structures.

Overview Of The PowerFLOW Software Portfolio

The PowerFLOW software portfolio consists of the following software packages:

PowerACOUSTICS – Aeroacoustics analysis:  PowerACOUSTICS is the industry leader in digital acoustic and aeroacoustics solutions for aerospace, transportation, and heavy equipment industries. It enables engineers to identify noise sources and improve noise performance. PowerACOUSTICS also provides access to noise and digital certification metrics, so you can be confident that your product meets noise regulatory requirements.

PowerVIZ – CFD visualization: PowerViz enables visualization and analysis of PowerFLOW results interactively.  PowerViz is a state-of-the-art visualization software that can interactively move slices, point probes, streamlines, and particle sources, as well as creating eye-catching pictures and animations of the flowfield. The ability to use Python scripting to automate your CFD post-processing workflow immensely increases productivity and results analysis turnaround time.

PowerDELTA – Geometry clean-up and Mesh creation: PowerDELTA streamlines surface mesh creation for PowerFLOW simulations, delivering high-quality results up to 75% faster. It automates gap fixes in CAD models and connects simulation insights to design, improving workflows and product development for leading manufacturers.

PowerTHERM and PowerCOOL – Thermal management: PowerTHERM, integrated with PowerFLOW, delivers a comprehensive thermal management solution, predicting surface temperatures and heat fluxes from radiation, conduction, and convection. It enables accurate temperature predictions and flow visualization for entire vehicles, helping identify and resolve thermal issues. PowerCOOL models heat exchangers like radiators and charge-air coolers for under-hood cooling analysis. Coupled with PowerFLOW, it predicts heat exchange and provides insights into air and coolant temperature distributions, helping optimize heat exchanger placement and overall vehicle design.

PowerINSIGHT: PowerINSIGHT simplifies simulation workflows by enabling configuration and submission of templates, from full simulations to post-processing. It allows interactive result browsing, automated comparisons, and report generation, helping teams maximize simulation value with improved automation, consistency, and insights.

Summary Of Advantages Of LBM-based CFD Over Navier-Stokes

Computational efficiency

  • LBM: Linear equations are solved on a lattice grid. Implementation is easier and computational time is relatively fast (up to 10x faster than Navier-Stokes).
  • Navier-Stokes: Complex PDEs solved using iterative methods, which can be complex and computationally expensive.

Parallelization

  • LBM: Easily parallelizable due to the local description of the flow and the simple lattice structure. Highly scalable and efficient on parallel and distributed systems, including GPUs.
  • Navier-Stokes: More complex to parallelize due to non-local description of flow, and careful scaling studies need to be performed to maintain proper communication and load-balancing, especially for unstructured meshes. 

Complex physics

  • LBM: Since LBM captures particle interactions at the mesoscopic scale, complex physics requires simpler physical models (multiphase flows, porous media, etc.).
  • Navier-Stokes: Complex physics require complex physical models, which can be computationally expensive.

Grid generation

  • LBM: More straightforward to set up and modify, especially for complex geometries. Lattice grid generation is simpler since only structured meshes are employed.
  • Navier-Stokes: Fine scale meshes for complex geometries can be difficult and time consuming to generate.

Time-stepping

  • LBM: More straightforward to set up and modify, especially for complex geometries. Lattice grid generation is simpler since only structured meshes are employed.
  • Navier-Stokes: Can be solved in steady or unsteady flows. Requires user to define timestep size for accurate time resolution and proper convergence.

Final Thoughts

In conclusion, PowerFLOW stands out as a cutting-edge CFD software powered by the Lattice Boltzmann Method, offering unparalleled capabilities for simulating real-world fluid flow scenarios. Its inherently transient, high-fidelity approach, combined with ease of use, scalability, and support for complex physics, makes it an invaluable tool across industries such as aerospace, defense, and transportation. The PowerFLOW suite, with its comprehensive portfolio of tools like PowerACOUSTICS,PowerTHERM, PowerDELTA, and PowerVIZ empowers engineers to optimize designs, streamline workflows, and achieve accurate predictions efficiently.

At Fidelis, we are resellers and expert users of PowerFLOW, providing expert technical support. Contact our expert team to learn more today!

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