Extendsive Inc.: Authorized Distributor of XFlow CFD in North America
Extendsive Inc.:  Authorized Distributor of XFlow CFD in North America

The Challenge of Traditional CFD

In the traditional mesh-based approach, the reliability highly depends on the quality of the mesh, and engineers spend most of the time working on the discretization.  Furthermore, there are severe difficulties in dealing with the changes in the topology of the domain for problems involving the presence of moving parts or fluid-structure interaction.

Why is XFlow so different to the current CFD solutions?
Simple – particle-based approach that avoid the traditional meshing process.


XFlow is a next generation CFD software system that uses a proprietary state-of-the-art Lattice Boltzmann technology specifically designed accurate flow simulation, transient aerodynamics, water management and fluid-structure interaction.  The XFlow approach to CFD simplifies the workflow, minimizes the presence of algorithmic parameters and avoids the traditionally time consuming meshing process.


With XFlow, complex modeling becomes both easier and more affordable.  With XFlow's speed and extensive use of parallel processing technolgy, it has become faster as well.

How is XFlow different? What is going on inside?


Beyond Lattice Boltzmann


XFlow is built on a Lattice-Boltzmann Method (LBM) solver.  In non-equilibrium statistical mechanics, the Boltzmann equation describes the behavior of a fluid modeled at mesoscopic scale. The Boltzmann equation is able to reproduce the hydrodynamic limit, which is where traditional Navier-Stokes CFD software lives, but can also model rarified media with applications to aerospace, microfluidics or even near vacuum conditions.


In addition, as opposed to standard LBM approaches, the scattering operator in XFlow is implemented in central moment space, naturally improving the Galilean invariance, the accuracy, and the stability of the solution.


Meshless Particle-based Kinetic Solver


XFlow features a novel particle-based kinetic algorithm that has been specifically designed to perform very fast with commercially available hardware.  The discretization approach in XFlow avoids the classic domain meshing process and the surface complexity is not a limiting factor anymore. The user can easily control the level of detail of the underlying lattice with a small set of parameters, the lattice is tolerant to the quality of the input geometry, and adapts to the presence of moving parts.

Adaptive Wake Refinement


XFlow automatically adapts the resolved scales to the user requirements, refining the quality of the solution near the walls, dynamically adapting to the presence of strong gradients and refining the wake as the flow develops.


Turbulence Modeling with High fidelity WMLES


XFlow features the highest fidelity Wall-Modeled Large Eddy Simulation (WMLES) approach to the turbulence modeling.

The underlying state-of-the-art LES, based on the Wall-Adapting Local Eddy (WALE) viscosity model, provides a consistent local eddy-viscosity and near wall behavior. It also performs in CPU-times similar to most codes providing just RANS analysis.


Single Consistent Wall Model


XFlow uses a unified non-equilibrium wall function to model the boundary layer. This wall model works in most cases, meaning that the user do not have to select between different models and take care of the limitations related to each scheme.


Advanced Analysis Capabilities

  • Thermal Analysis
  • Flow through Porous Media
  • Non-Newtonian Flows
  • Conjugate Heat Transfer
  • Complex boundary conditions
  • Multiple moving parts or moving boundaries with 6 d.o.f. movement definition

For more information, or for questions about a specific application, contact us here.

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