Flow - Recent Threads

How to create and run multiple simulations in Fidelity CFD using Python API

Gaurav — Mon, 10 Nov 2025 07:09:15 GMT

The script can be used to create and simulate multiple duplicate simulations within Fidelity 2025.1, specifically targeting Tutorial 1 of the Fidelity software. The script utilizes Fidelity Python functions.

You may refer to the Fidelity Python API documentation for more details, specifically the "fidelity.gui", "fidelity.project", and "fidelity.simulation" modules, which fall under the "BASE MODULES" and "SIMULATION MODULES" sections, as almost all the functions used in this article are derived from these modules.

How to create and run multiple simulations in Fidelity CFD using Python API

Francis Turbine Workflow: Geometry to Results Analysis with Fidelity

Gaurav — Tue, 30 Sep 2025 14:10:10 GMT

Are you looking to streamline your simulation setup process and unlock the full potential of Python scripts? This RAK (Rapid Adoption Kit) is designed to make your simulation experience smoother, more efficient, and more effective.

Benefits of Using RAK:

Rapid Setup: With RAK, you can quickly and easily set up several powerful Fidelity modules, ensuring a seamless experience from the start.

Comprehensive Module Integration: The script utilizes a range of modules, including project, GUI, geometry, domain setup, meshing, grid creation, material properties, simulation, and analysis. These modules work together perfectly, making it easy to establish your simulation environment.

Easy Integration with Fidelity Plugins: The Euranus parameters module allows you to effortlessly integrate Python functions into your simulation and meshing workflows.

The GAMM turbine, a specific model of the Francis hydraulic turbine, has been used as a test case in the 1989 GAMM workshop. This model is widely used in power generation and has been extensively tested in laboratory settings. With RAK, you can easily set up and simulate this model, and many others like it.

Don't miss out on the opportunity to take your simulations to the next level. Try RAK today and experience the power of streamlined simulation setup

Francis Turbine Workflow: Geometry to Results Analysis with Fidelity

Setting Up a Simulation Environment with Python Script for Fidelity Modules.

Gaurav — Wed, 02 Jul 2025 08:07:49 GMT

Unlock efficient simulation setup with our Python script, tailored for Fidelity 2024.2. This innovative solution leverages a suite of specialized modules to create a seamless simulation environment. With automatic configuration and compatibility analysis, you'll enjoy a smooth user experience. Key features include:

- Streamlined setup process with geometry, domain, and meshing modules
- Effortless integration of Python functions into meshing workflows
- Comprehensive simulation environment with 24 circular fins and customizable channel dimensions
- Fast-tracked and automated approach to simulation setup

Script-Based Workflow for Circular Fins: From Geometry to Mesh Generation

Simplifying simulation cloning with Python scripting

Gaurav — Tue, 03 Jun 2025 07:32:19 GMT

Optimized for Fidelity 2024.2, this script offers a seamless simulation setup experience. It provides an automated guide to duplicate simulations. Parametric studies are facilitated through boundary condition modification. Utilizing Fidelity Python functions, the setup is streamlined.

https://support.cadence.com/apex/ArticleAttachmentPortal?id=a1OPP000001DsBh2AK&pageName=ArticleContent

RE: Simplifying simulation cloning with Python scripting

KD202502275710 — Tue, 03 Jun 2025 13:38:33 GMT

This is indeed awesome. Very helpful

RE: Simplifying simulation cloning with Python scripting

Gaurav — Tue, 03 Jun 2025 11:31:18 GMT

Hello KBB,

In this computational domain, it can be observed that the plugins for "hexpress_parameters" are required. However, the function associated with "from Solution" is not defined under the "hexpress_parameters" module. Consequently, the module "euranus_parameters" is utilized instead.

The "euranus_parameters" module is specifically designed for turbo applications. It is assumed that the development team will define the "from_solution" functionality for both modules in future versions.

RE: Simplifying simulation cloning with Python scripting

KBBKBB — Tue, 03 Jun 2025 10:33:30 GMT

Thanks for the insights, Gaurav!

Unfortunately, I’m a bit confused about these two lines:

Why is this being done again?

Also, as you can see, the word "type" is highlighted differently. I looked it up and found that it can be used either as a function or as a metaclass (whatever taht means).

On top of that, the get_initial_solution_choice() function returns a string — specifically, one of the following: 'Constant values', 'Turbo', 'Techno effects', or 'From solution'. What do we need that for? "Type" and "dom_params" are not used afterwards in the code.

So I’m a bit lost here.

RE: Automated continuous computation of operating conditions using FIDELITY

KBBKBB — Tue, 03 Jun 2025 07:20:41 GMT

One effective approach is to automate the process using the Python API — I recently implemented something similar.

Start by running an initial simulation. If it converges successfully, duplicate the simulation and modify the mass flow or outlet pressure by a defined step size. Use the result of the previous simulation as the initial solution for the next one (make sure to disable CGI). Repeat this process to generate a performance curve.

This will result in a series of simulations for the same setup, each with adjusted boundary conditions.

It’s important to monitor convergence by evaluating key metrics such as mass flow, efficiency, or other relevant values over the last XXX iterations.

If you're approaching the surge line, you can refine your step size for changing the mass flow or outlet pressure dynamically. For example, if a simulation at mass flow X converges but the next at X + step_size fails, reduce the step (e.g., try X + step_size / 2). This allows for a controlled and gradual approach to critical operating points.

To get startet with Python and Fidelity: check the documentation. Some Fidelity tutorials include example Python scripts.
It’s also worth checking out the posts by Gaurav — he provides detailed explanations and examples of how to use Python with Fidelity.

Cheers

Automated continuous computation of operating conditions using FIDELITY

HY202504134411 — Tue, 27 May 2025 09:50:28 GMT

When using FIDELITY to calculate compressor performance curves, how to achieve automated continuous computation of different operating conditions by altering the mass flow rate outlet conditions?

RE: Automated continuous computation of operating conditions using FIDELITY

Gaurav — Thu, 29 May 2025 10:08:48 GMT

Fine Turbo offers a direct option, however, this feature is not supported by the Fidelity software. As a result, the corresponding Python functions, which are linked to the Fidelity software's features, are not functional. Nevertheless, a fully functional Python API is available for Fine Turbo, and more information can be found in the Fine Turbo documentation.

RE: Automated continuous computation of operating conditions using FIDELITY

HY202504134411 — Thu, 29 May 2025 08:21:01 GMT

Is it really impossible to achieve this functionality through the Python API?

RE: Automated continuous computation of operating conditions using FIDELITY

Gaurav — Thu, 29 May 2025 06:19:27 GMT

To the best of my knowledge, the Fidelity software does not currently support this feature. However, it is available in the legacy version, Fine Turbo, which can perform the desired operations.

Automating Channel Flow Simulation Using Fidelity Python API: A Step-by- Step Guide

Gaurav — Tue, 13 May 2025 13:28:09 GMT

The Fidelity 2024.1 script file guides users through essential operations, ensuring a seamless workflow. Key features include geometry creation and domain setup, comprehensive meshing, simulation, and postprocessing. The script provides flexible and efficient techniques for each step, allowing for customizable setups. It also covers postprocessing techniques to analyze results effectively and gain insights from simulations.

https://support.cadence.com/apex/ArticleAttachmentPortal?id=a1OPP000000nbzJ2AQ&pageName=ArticleContent

Flux dispersion method

WS202504245114 — Fri, 25 Apr 2025 02:26:36 GMT

How to view convective flux and viscous flux in the numerical method section in Numeca FineTurbo.

RE: Flux dispersion method

Gaurav — Mon, 28 Apr 2025 08:38:14 GMT

The convective flux describes the transport of a quantity, such as momentum, heat, or mass, due to the bulk movement of a fluid. It is represented by a term in the governing equations that involves the fluid velocity and the property being transported. For example, in momentum transport, the convective momentum flux is given by ρvv, where ρ represents density and v represents velocity.

The viscous flux arises from the internal friction within the fluid, which creates stresses that transfer both momentum and heat. It is represented by terms in the governing equations that involve derivatives of the velocity field and the fluid viscosity. In the Navier-Stokes equations, the viscous flux terms account for the effects of viscosity on momentum transport.

You can visualize the velocity field and other properties, such as temperature or concentration. The simulations can demonstrate convective flow patterns and the impact of viscosity on the flow. Additionally, you can visualize the results, including velocity vectors, streamlines, and temperature or concentration profiles.

Overview of DNS, LES, and RANS Turbulence Models

CFDTech — Tue, 11 Feb 2025 09:18:11 GMT

Direct Numerical Simulation (DNS) DNS requires no modeling, but it demands resolution from the large scales all the way through at least the beginning of the dissipation scales. As a result, this approach requires a significant amount of computational resources, leading to a total arithmetic scaling of at least Re^3.

Large Eddy Simulation (LES) LES requires modeling of part of the inertial subrange and into the beginning of the dissipation scales. The amount of required modeling is determined by the amount of resolution that can be afforded, but it is unlikely that the total arithmetic will scale worse than Re^2.

Reynolds-Averaged Navier-Stokes (RANS) RANS requires modeling everything from the integral scales into the dissipation range, with only mean (zero th –mode) quantities being directly computed. Consequently, the total arithmetic is, at most, a weak function of the Reynolds number (Re), meaning that the computational cost does not increase significantly with increasing Reynolds number.

Autogrid Mesh to openFoam

sima101f — Sat, 28 Sep 2024 21:10:46 GMT

Dear Numeca Team,

I am currently working on benchmarking CFD results for a turbomachinery simulation. As part of this process, I am attempting to use a previously generated mesh for OpenFOAM. After converting the mesh in AutoGrid5 and checking its quality with the checkMesh command in OpenFOAM, I encountered the following error: “Distance between the center of patch XY and transformed center of patch UV is greater than the match tolerance of XY for the patch.” (Note: Patches XY and UV are located on either side of the periodicity.) I suspect this issue is related to the options chosen during the AutoGrid setup. I’ve tried modifying the size of the overall domain to fit the rotor and tested both matching and non-matching periodicity settings, but unfortunately, none of these attempts resolved the issue. I would greatly appreciate any guidance or suggestions on how to address this

RE: Autogrid Mesh to openFoam

sima101f — Mon, 09 Dec 2024 11:41:05 GMT

Thank you for the answer, I am certainly aware of this fact. These recommendations are the reason I altered my meshing and why I used the advanced skewness control. But the issue of the bad cells arises AT first cell at the blade surface.

It looks like the cells are sheared for some reasons.

RE: Need help on modeling of Realizable k-epsilon turbulence viscosity

Gaurav — Mon, 11 Nov 2024 09:18:00 GMT

The decomposition of U* and W appears accurate for 2D flow. Which software are you using, Fidelity or Fine Products?

Need help on modeling of Realizable k-epsilon turbulence viscosity

AL202410221044 — Wed, 23 Oct 2024 04:00:11 GMT

Dear community,

I am having a question that need your help reading the modeling of Realizable k-epsilon turbulent viscosity.

In this model, CMU is varied instead of a constant value as in the standard model. In that, some additional equations is used for calculate the CMU, including:

U*=sqrt(S_ij*S_ij+Ω_ij*Ω_ij)

Ω_ij= 0.5*(∂u_i/∂x_j - ∂u_j/∂x_i )

S_ij= 0.5*(∂u_i/∂x_j + ∂u_j/∂x_i )

and

W=S_ij*S_jk*S_ki/Š³

S=sqrt(S_ij*S_ij)

I wonder for the two-dimensional (2D) simulation, the U* and W will be expressed as follows???

U* = sqrt(S₁₁*S₁₁+S₂₂*S₂₂+2*S₁₂*S₁₂+2*Ω₁₂*Ω₁₂)

W = (S₁₁^3+S₂₂^3+3*S₁₂^2*(S₁₁+S₂₂))/S^3

with S=sqrt(S₁₁*S₁₁+S₂₂*S₂₂+2*S₁₂*S₁₂)

Thank you for your help.

customized gaps

WS202410062051 — Mon, 07 Oct 2024 06:08:17 GMT

If you select the .dat file in the defined shape, how should you write the face you want to use in this file, which is the format in the .dat file?

RE: customized gaps

Gaurav — Mon, 07 Oct 2024 11:53:46 GMT

This is a duplicate query. The original query has already been answered in the original post.

RE: customized gaps

Gaurav — Mon, 07 Oct 2024 11:51:07 GMT

You can visit support.cadence.com to find the IGG User manual and refer to Chapter 12 for instructions on writing the .dat file.

Please review Chapter 6, "Hub/Shroud Partial Gaps Control," in the "AutoGrid5" user guide manual. Additional information about the "Defined Shape" can be found, and for the .dat format, details are available in the "Curve data files of Igg User Manual."

customized gaps

WS202410062051 — Mon, 07 Oct 2024 06:13:09 GMT

If you select the .dat file in the defined shape, how should you write the face you want to use in this file, which is the format in the .dat file?

RE: Autogrid Mesh to openFoam

Gaurav — Mon, 30 Sep 2024 06:16:22 GMT

Please provide information about the Fine Turbo and OpenFoam software versions.
Please navigate to support.cadence.com, where you can search for the "AUTOGRID" manual and go through the "Export—> OpenFOAM."
Referring to your error, I am attaching some parts of the documentation. Please go through them.