Fidelity™ Flow Density-based Solver

NUMECA is now Cadence

Speed and precision combined to solve multiphysics challenges

Multiphysics problems require a variety of advanced and flexible solutions. Fidelity™ Flow allows engineers to solve multi-phase, -fluid,
and -species challenges with both the fastest technology on the market and a freely customizable interface that can be tailored to specific applications.


The Fidelity™ Flow solution includes access to the trusted FINE™/Open tool.


External aerodynamics for all speeds, from incompressible to supersonic

High-speed external flows can be a challenging endeavor, especially at transonic or supersonic to hypersonic speed.

With the Flow solver and its density-based formulation, modeling flows that reach Mach numbers up to 20 for re-entry is a breeze.

The capabilities of the solver ensure fast and accurate flow solution, even for the most complex cases.

For a detailed study on supersonic aircraft design   Read more


Modeling combustion applications implies handling multiple species together with complex physical and chemical reactions. Conjugate heat transfer and radiation have a large impact on the control of the temperature distribution and on combustion efficiency.

To respond to these requirements, Fidelity™ Flow offers several modeling strategies including the classical flamelet, the hybrid BML/flamelet method, and the Flamelet Generated Manifolds method (FGM) to analyze the range of purely non-premixed gaseous to purely premixed combustion applications.

The combustion model can be coupled with pollutant prediction, radiation, and conjugate heat transfer analysis.

For  a case study on combustion and radiative heat transfer in a generic gas turbine (GGT)

Read more


Cavitation occurs in liquid flows when the pressure drops below the saturation pressure. It is observed in pumps, nozzles, injectors, marine propellers and underwater bodies and often causes loss in efficiency, increase of noise level, structural damages or erosion.

Our software offers three modelling approaches to analyze cavitation: the barotropic law, thermo-tables, and transport-equation modeling.

Our experience extends to cryogenic flow simulations, with advanced modeling for cavitation and phase change in thermo-sensitive fluids.

For a detailed example    Read more

Cavitation inception: Left, no local refinement - Right, dynamic mesh adaptation

Multispecies, particle flows and sprays

Multiphysics applications often involve two or more fluids of different nature or of different phases of the same fluid. These form mixtures and interactions occur between each.

The Open solver offers a wide range of multifluid modeling approaches whose domain of application depends on the physical properties, concentration and homogeneity of the mixture.

The thermo-tables fluid definition captures the phase change phenomena. The inert or reacting multispecies model describes the mixture of gases or liquid such as pollutant tracking. The Lagrangian particles model tracks the motion of dilute dispersed particles and their interaction with the main phase, for example sprays, particulate flows, cyclones. These models can be coupled with all other physical phenomena of the multiphysics environment.

Develop and customize freely

The OpenLabs™ module provides a simple and easy-to-learn syntax that allows the user to customize most of the routines of the solver, including adding or editing source terms, equations, controlling the initialization, the fluid properties or the boundary conditions.

These modifications are automatically compiled, which makes them execute as fast as if they were implemented in the solver source code.

Full-engine CFD simulation

Computation of a full engine using Fidelity™ Flow's NLH and combustion models

Would you like to know more?  


With the purpose of meeting future aircraft engine requirements in terms of low emissions, high reliability and efficiency, a novel highly efficient fully-coupled RANS-based approach has been developed, enabling the simulation of a full aero-engine within a single code.

One of the advantages of a fully coupled approach over a component-by-component approach is that the boundary conditions at the interfaces do not need to be guessed.

A Smart Interface methodology ensures a direct coupling between the different engine components, compressor- combustor-turbine, and allows the CFD models to vary between each component within the same CFD code.

For the simulation of the combustion process, the Flamelet Generated Manifold (FGM) method is applied. While the approach is superior to classical tabulated chemistry approaches and reliably captures finite-rate effects, it is also computationally inexpensive.

The Nonlinear Harmonic method is used to model the unsteady interaction between the blade rows as well as the influence of the non-homogeneities at the combustor outlet on the downstream turbine blade rows. This method is 2 to 3 orders of magnitude faster than a classical URANS simulation.

Nonlinear Harmonic for every configuration

Gain 3 orders of magnitude in solving speed for unsteady simulation.

The presence of components such as hoods, collectors, or volutes can be taken into account for a better assessment of the performance of the turbomachinery.  Non-axisymmetric pressure variations can be modeled with the Nonlinear Harmonic method, with domains that can be non-periodic and meshed with mixed grids.  

With the Non-Linear Harmonic method, users can solve transient behavior 100 times faster than a classic unsteady analysis, capturing phenomena like clocking, blade row interactions, tonal noise, inlet distortion...

This unique technique computes the unsteady flow field by means of the Fourier decomposition of the periodic fluctuations, based on a pre-selected number of harmonics, typically associated with the blade passing frequencies and their multiples.    

Would you like to know more?    VIEW WEBINAR

Impeller volute - Image courtesy of Liebherr

Fluid-Structure Interaction




Fluid-Structure Interaction (FSI) occurs when a fluid flow deforms a structure which in return influences the flow field.

The significance of aeroelastic instabilities has increased substantially in the last few decades, particularly in the industry of aviation and turbomachinery. A continuous trend towards lightweight and cost-efficient design forces engineers to push the boundaries in the design phase with the risk of leading to vibratory stresses and, in the worst case, to vibratory failure. Cadence offers several approaches to predict fluid-structure interactions depending on:

  • the direct coupling between the flow and the structural solvers, 
  • the use of the coupling server MpCCI, which manages the communication and the interpolation of coupling data between the fluid and structure solvers, 
  • or the modal approach in the flow solver that takes advantage of the harmonic solution of the NLH method and solves the modal equations, to compute the global deformation of the structure written as a composition of mode shapes, removing the necessity of interpolation between fluid and solid domains. 

For an interesting case about wing flutter     Read more

Turnaround time up to 20x faster than any other solution on the market

The Fidelity™ Flow CFD solution is optimized by scaling linearly on thousands of CPU cores, as well as on GPU.

Combined with our patented CPUBooster™ technology, a unique convergence acceleration technique, computation time is reduced even further.

The total package renders the solution up to 20 times faster than any other solution on the market.

We massively invested in NUMECA solutions more than 2 years ago, and are very satisfied with the level of precision they provide us.

Dr.Takiguchi, Chief Engineer at Honda Automobile R&D Center


"Masten Space Systems heavily utilized the FINE Suite at HPC scale to design our next-generation reusable satellite launch system." 

Allan Grosvenor, Aerodynamics Lead at Masten Space Systems


Key Features

Fidelity™ Automesh Hexpress:

  • Full Hexahedral Grids (no prism, no tetrahedra, no pyramid)
  • Direct CAD import capabilities
  • CAD manipulation and decomposition tools
  • Mesh wizard for rapid solution set-up and easy back and forth operation
  • Buffer cell and boundary layer insertion for high quality cells in boundary layer regions
  • Automatic refinement procedures based on user defined sensors either next to solid walls or at specified area in the domain
  • Multi domain capabilities allowing the treatment of CHT and multi-part geometry models
  • Full non-matching multi-block connection, allowing multi-row turbomachinery meshing

Density-based flow solver:

  • One single code for all types of fluids (incompressible, low-compressible, condensable and fully compressible) and speed (low speed to hypersonic regime)
  • Acceleration with the CPU-Booster™ module provides 3-5 times gain in convergence speed
  • Embedded fluid structure interaction with the Modal and Flutter Analysis module
  • Multigrid convergence acceleration
  • Multidomain capability
  • Combustion
  • Radiation
  • Lagrangian multiphase
  • Cavitation
  • Multispecies reacting flows
  • Thermodynamics tables and combustion tables generation
  • Python scripting technology


  • OpenLabs™ allows users to customize or add physical models
  • Flexible and user-friendly Graphical User Interface
  • Users don’t need to care about programming details and code structure
  • OpenLabs can be used in a wide variety of industrial and academic applications
  • Identical computing and memory costs compared to source-coded models
  • Free access to all Open community


  • Multi-projects and multi-views graphical user interface
  • Python scripting technology
  • Surface and 3D local value
  • Iso-lines
  • Color contour
  • Vector
  • Iso-surfaces
  • Cloud of particles
  • Line chart
  • Integral
  • Formula and operator derived quantities
  • Live co-processing


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