====== Ansys Fluent/Aero/Icing Help ====== > Ansys Fluent is the industry-leading fluid simulation software known for its advanced physics modeling capabilities and industry leading accuracy. * See: https://www.ansys.com/products/fluids/ansys-fluent * Fluent users guide: https://ansyshelp.ansys.com/public/account/secured?returnurl=/Views/Secured/corp/v252/en/flu_ug/flu_ug.html ---- ===== Running ===== To use ANSYS Fluent on Comet, please read the main [[:advanced:software:ansys|ANSYS guide]] first. ---- ===== Fluent tools ===== A number of tools are included in the Fluent component of our ANSYS license. Those which you can directly run on Comet are listed below. You may also want to consult: * [[advanced:software:ansys|ANSYS guide]] - our main ANSYS guide for Comet * [[advanced:ansys_workbench|ANSYS Workbench guide]] - using ANSYS Workbench on Comet ---- ===== aero ===== To start the Fluent Aero workspace, first launch a new [[advanced:software:x11|X11 desktop session]] using our [[advanced:interactive|Open OnDemand]] service. Once the VNC Desktop session is running, launch a the terminal application from the bottom bar: {{:advanced:software:ansys_desktop_terminal.png?800|}} In the terminal, enter the following commands: $ source /nobackup/shared/containers/ansys.2025r2.sh $ container.run bash > aero The Fluent Aero workspace application will open: {{:advanced:ansys_fluent_aero.png?800|}} Functionality, the Aero workspace works the same as the main Fluent application. ---- ===== fluent ===== ANSYS Fluent can be run in either batch mode for long, complex compute jobs, or interactively via the graphical application running on Open OnDemand. Both approaches are covered below. ==== Sample batch job - Single Node ==== This example requires testing Running Fluent on a single node (aka a server) is the easiest method, but you are limited by the resources available on that single node (//maximum of 256 cores and 1.5TB of RAM//). The example below allocates: * A single node * 32 parallel Fluent tasks, each with one CPU core (//total 32 cores//) * 128GB RAM in total * 8 hours of runtime * Uses a Slurm partition named 'default_free' Adjust the values as needed. #!/bin/bash #SBATCH --nodes=1 #SBATCH --ntasks-per-node=32 #SBATCH --cpus-per-task=1 #SBATCH --mem=128G #SBATCH --time=08:00:00 #SBATCH --partition=default_free source /nobackup/shared/containers/ansys.2025r2.sh container.run fluent 2d -i myfluentjob.jou -gu -t $SLURM_NTASKS -driver null Submit the job as **sbatch fluent_single.sh** ---- ==== Sample batch job - Multi Node ==== This example requires testing Multi-node Fluent jobs can take advantage of more resources simultaneously, but the script is a little more complex. The example below allocates: * 4 nodes * 4 parallel Fluent tasks per node, each with 8 cores (32 per node), for a total of 16 Fluent tasks and 128 CPU cores (''4 nodes x 4 tasks x 8 cores'') * 64GB RAM per node, for a total of 256GB RAM (''4 nodes x 64GB per node'') * 8 hours of runtime * Uses a Slurm partition named 'default_free' Adjust the values as needed. #!/bin/bash #SBATCH --chdir=/path_to/your_ansys/working_directory/ #SBATCH --nodes=4 #SBATCH --ntasks-per-node=4 #SBATCH --cpus-per-task=8 #SBATCH --mem=64G #SBATCH --time=08:00:00 #SBATCH --partition=default_free HOSTNAMES=`scontrol show hostnames $SLURM_JOB_NODELIST` echo "Job will run on: $HOSTNAMES" source /nobackup/shared/containers/ansys.2025r2.sh # Now run ansys.... # -i : the name of your input file # -gu and -driver null : to disable the graphical user interface # Running on normal nodes (not low-latency) srun container.run fluent 3ddp -g -nm -np ${SLURM_NTASKS} -nt ${SLURM_CPUS_PER_TASK} -slurm -pdefault -mpi=intel -platform=intel -i MY_PROJECT.JOU # If running on low-latency nodes (uses infiniband inter-process communication) #srun container.run fluent 3ddp -g -nm -np ${SLURM_NTASKS} -nt ${SLURM_CPUS_PER_TASK} -slurm -pinfiniband -mpi=intel -platform=intel -i MY_PROJECT.JOU Submit the job as **sbatch fluent_multi.sh** //Note: Multi node example taken from// https://innovationspace.ansys.com/forum/forums/topic/multiple-nodes-using-fluent-on-hpc-under-slurm/ Further examples may be found at https://docs.hpc.shef.ac.uk/en/latest/stanage/software/apps/ansys/fluent.html You may need to do some performance profiling to understand whether it is better to have __more__ tasks with fewer cpu cores per task, or __fewer__ tasks with more cpu cores per task, e.g: * ''--ntasks-per-node=4'' //and// ''--cpus-per-task=8'' //or//... * ''--ntasks-per-node=8'' //and// ''--cpus-per-task=4'' This represents the //same// number of cores, but presented via a //different// mix of tasks. Some experimentation may be needed in order to find the most optimal balance of task quantity and task size. ---- ==== Example graphical job ==== To start the graphical Fluent tool, first launch a new [[advanced:software:x11|X11 desktop session]] using our [[advanced:interactive|Open OnDemand]] service. Once the VNC Desktop session is running, launch a the terminal application from the bottom bar: {{:advanced:software:ansys_desktop_terminal.png?800|}} In the terminal, enter the following commands: $ source /nobackup/shared/containers/ansys.2025r2.sh $ container.run bash > fluent The Fluent Launcher window opens: {{:advanced:ansys_fluent_launcher.png?800|}} Start a //new// project - make the following settings changes: * **Parallel Settings** -> Shared Memory on local machine * **Scheduler** -> None If loading an //existing// project: * **Home** -> Solution -> Read -> Case -> Select your input data Now press the **Start** button, the main Fluent application opens, either with a blank window: {{:advanced:ansys_fluent_new.png?800|}} ... or your existing project if you chose to load one: {{:advanced:ansys_fluent_load.png?800|}} ---- ==== Testing Fluent ==== A copy of an interactive Fluent job is kindly provided by one of our postgraduate researchers, below: * {{ :advanced:fluent_example.tar.gz|}} To use this example to test Fluent, copy the ''.tgz'' to your home directory, extract it (''tar -zxf fluent_example.tar.gz'') and then follow these steps: **Option 1** * Start the ''fluent'' launcher as described above * In the launcher window navigate to **Home** -> Solution -> Read -> Case -> and select the file ''animation/pulse_pipe_fluid_vol_transient_exp.cas.h5'' from your home directory * Click **Start** in the launcher window, the Fluent application starts * In the outline view on the left panel of the Fluent application window navigate to **Case View** -> //Solution// -> then right click //Initialization// and choose //Initialize// * In the outline view on the left panel of the Fluent application window navigate to **Case View** -> //Solution// -> //Calculation Activities// -> then right click //Run Calculations// and choose //Calculate// * Once solution is completed choose the **File** menu then -> //Write// -> //Case & Data// **Option 2** * In the top menu choose the **File** menu then -> //Read// -> //Journal// -> and choose ''animation/solve0.jou'' from your home directory ---- ===== icing ===== To start the Fluent Icing workspace, first launch a new [[advanced:software:x11|X11 desktop session]] using our [[advanced:interactive|Open OnDemand]] service. Once the VNC Desktop session is running, launch a the terminal application from the bottom bar: {{:advanced:software:ansys_desktop_terminal.png?800|}} In the terminal, enter the following commands: $ source /nobackup/shared/containers/ansys.2025r2.sh $ container.run bash > icing The Fluent Icing workspace application will open: {{:advanced:ansys_fluent_icing.png?800|}} Functionality, the Icing workspace works the same as the main Fluent application. ---- ===== post_analysis ===== To start the ''post_analysis'' tool, first launch a new [[advanced:software:x11|X11 desktop session]] using our [[advanced:interactive|Open OnDemand]] service. Once the VNC Desktop session is running, launch a the terminal application from the bottom bar: {{:advanced:software:ansys_desktop_terminal.png?800|}} In the terminal, enter the following commands: $ source /nobackup/shared/containers/ansys.2025r2.sh $ container.run bash > post_analysis The ''post_analysis'' application interface will open: {{:advanced:ansys_fluent_postanalysis.png?800|}} ---- ===== udil2udil ===== The ''udil2udil'' tool does not need to be run in a graphical session and can be used from either a command line or desktop environment. $ source /nobackup/shared/containers/ansys.2025r2.sh $ container.run udil2udil -h udil2udil Usage: udil2udil [-v] [-h] infile outfile Options: -h Display this information -fps [fps] Change the fps for the output movie -options [opts] Change the writer options for the output movie -v Enable verbose mode ---- [[:advanced:software:ansys|Back to ANSYS]] [[:advanced:software|Back to Software]]