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

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?

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.

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.

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 06:13:09 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?

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?

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

R-cycle in Open solver

cfd enthusiast — Sun, 01 Sep 2024 14:44:27 GMT

Hello Everyone,

I have been simulation using the pressure based solver in fidelity and I noticed that my simulations work well using the R-cycle (Robust-Cycle) within the algebric multigrid Method. I don't know why that is. I tried looking for the steps of that algorithm online, however I didn't find anything on it. Is the algorithm for the R-cycle known by another name?

Thank you!

Flow of CFD tools

RohitRohan — Mon, 12 Aug 2024 14:57:04 GMT

Dear Community,

I am electronics and communication engineer and I am currently working on PCB design products, next I am starting for mechanical software such as CFD, but as a electronics background I have no idea about the mechanical engineering.

Can anyone guide me for the CFD products, like I see many products under CFD, like Pointwise, Turbo etc.

I want to know the flow, like if I have a CAD file for Car, eg BMW car, what are the products that is used for meshing, CAD cleaning, thermal simulation, air flow simulation, structural simulation, which are CFD tools that are associated for each and features and what is the flow of procedure, like if a car company such as BMW gives me a CAD model to simulate which are the products that I require and what is flow to complete all the requirements for company such as BMW.

Regards,

Rohit Rohan

merge two meshe files

sima101f — Fri, 24 May 2024 12:07:52 GMT

Hi.

Is there any way that i can merge two mesh files and make them a single case?

For eg. I have axial compressor meshed separately and my radial compressor meshed separtely. Now I wanted to run them together, but i don't want to mesh them again.

Thanks

Sid

Crash - Solver

TobiasB — Sun, 05 May 2024 12:51:13 GMT

Hello

Im am new to using FineMarine, and during the tutorials (Tutorial 5 - planning) i am having some trouble with the solver.

I dont seem to be able to upload a picture of the crash-report directly from my pc, however it says:

RUN INFO:

Pre-processing: Finished

Solver: Crashed

Post-Processing: Finished

Thanks in advance!

Boundary Layer Theory

CFDTech — Fri, 03 Nov 2023 06:18:33 GMT

Team CFDTech

Cadence Design Systems

Regarding estimating inertial data (Body and frame body motion - Dynamic parameters A, B, C, D, E, F).

Halder — Wed, 13 Sep 2023 09:08:58 GMT

Dear Sir,

I am writing this email regarding calculating the value of the A, B, and C matrix (IITC Regression law). I am getting different values A, B and C based on input software estimation and manual calculation.

Case 1:

Input value: z= 0.4526 m

Kxx/B=0.4; Kyy/L=0.25 and Kzz/L=0.25, L=7.2786 m

Output value (inertia matrix in body primary frame; 3D, half body):

A=274.96 [kg.m2]

B=6141.03 [kg.m2]

C=6141.03 [kg.m2]

E= D=F=0 [kg.m2]

Case 2(in 3D):

Manual calculation based on Kxx= 0.4076 m; Kyy= 1.82 m and Kzz= 1.82 m, m= 1648.2 kg

A=Kxx^2*m= 273.828256

B=Kyy^2*m =5459.49768

A=Kzz^2*m =273.828256

D=E=F=0.

Based on the software estimate and manual calculation both are different (Source: FINEMarine user guide, page 332). Therefore I request you to kindly clarify the difference between manual and software. Therefore, I request you kindly help me calculate this value.

Best regards,

Paresh Halder

Contra-rotating propeller simulation

TSB22CFD — Fri, 08 Sep 2023 18:27:12 GMT

I obtained a hexpress surface to volume mesh of the countra-rotating propeller (I followed the meshing tutoral "Meshing the PPTC Propeller using surface-to-volume meshing"). Should I add a rotating sub-domain or is it possible to make the individual props rotate withou it?

centrifugal compressor with vaneless diffuser

sima101f — Thu, 13 Jul 2023 10:30:03 GMT

Hello

I have created my centrifugal compressor with vanelles diffuser in cfturbo. when i try to import design in Autogrid it recognizes it as single row. Can somone please explain how can i have sepeate row for impeller and vaneless diffuser. Or is it okay to simulate as one ?

Thanks

Fidelity on compute cluster with Slurm scheduler

nopech — Tue, 13 Jun 2023 10:43:34 GMT

Hello everyone

What is the recommended way to use Fidelity on a compute cluster using the Slurm scheduler?

Let's say I automated a CFD workflow using the python interface. The script is usually executed like this

fidelity2023.1 -batch -noFork -print -script script_full_path/script.py

and the number of processors is specified in the script like this

my_sim.start_simulation(num_proc=8)

Can I run fidelity as mpi application, e.g.

mpiexec -n 8 fidelity2023.1 -batch -noFork -print -script script_full_path/script.py

and what do I need to specify the num_proc within the script?

Thank you

Fidelity Split along an ISO curve on primitives

nopech — Tue, 23 May 2023 09:21:07 GMT

Hello everyone

Since Interfaces have to consist of at least 2 patches, i have to cut my patch. Fidelity has this tool called "Split along an ISO curve" but it keeps finding excuses for not working. For example it is not working on primitives. Any alternatives? Maybe convert the primitive to non-primitive within Fidelity?

Thanks!

Imposing a fluctuating BC at the outlet

sriluta — Thu, 08 Dec 2022 11:44:36 GMT

Hey, maybe someone can explain me that. I am investigating a cascade flow in a turbine with very high pressure fluctuations. At the inlet domain I have a unsteady boundary condition.Now I am looking for a boundary condition for my outlet. I don't quite understand the following: I have a certain outlet area, i.e. the distance from the blade to the outlet. I extend this outlet range for example by 2 times. Then I start a simulation with a fixed boundary condition at the new outlet. If the flow now passes the first outlet but has not yet reached the second outlet, I extract the time-dependent condition there during the simulation and this extracted condition is then my outlet boundary condition at the desired location in the simulations.

greetings

Questions regarding OMNIS

Durai12 — Sun, 13 Nov 2022 17:02:13 GMT

Hello,

I have two queries and would greatly appreciate it if they could be answered:

1) Is there any tutorial for 2D simulations in OMNIS? Specifically 2D airfoil simulation

2) When I try to save my project, I get an error saying " Warning, unable to create directory". Any ideas on how to solve it?

Thanks in advance.

TabGen, dependent undependent Variable

sriluta — Fri, 15 Jul 2022 13:51:33 GMT

Hey together, I have some Questions to TabGen.

In principle, I am investigating the flow through a single-stage turbine. The fluid is a mixture and a calorically perfect gas.

In my simulation it is so that I define the total pressure and total temperature as well as the fluctuating inflow angle over the azimuth angle at the inlet and the static pressure at the outlet in the stationary simulation, which I use as initial solution for the transient simulation.

Now I have questions about the dependent variables in TabGen under main window. Are the dependent variables all except pressure and temperature ? And in this case especially the PT table