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HELYX is a comprehensive, general-purpose, computational fluid dynamics (CFD) software package for engineering analysis and design optimisation developed by ENGYS. The package features an advanced open-source CFD simulation engine and a client-server GUI to provide a flexible and cost-effective HPC solver platform for enterprise applications.

Using HELYX on Cirrus

HELYX is only available on Cirrus to authorised users with a valid license to use the software. For any queries regarding HELYX on Cirrus, please contact ENGYS or the Cirrus Helpdesk.

HELYX applications can be run on Cirrus in two ways:

  • Manually from the command line, using a SSH terminal to access the cluster’s master node.
  • Interactively from within the HELYX GUI, using the dedicated client-server node to connect remotely to the cluster.

A complete user’s guide to access HELYX on demand via Cirrus is provided by ENGYS as part of this service.

Running HELYX Jobs in Parallel

The standard execution of HELYX applications on Cirrus is handled through the command line using a submission script to control Slurm. A basic submission script for running multiple HELYX applications in parallel using the SGI-MPT (Message Passing Toolkit) module is included below. In this example the applications helyxHexMesh, caseSetup and helyxSolve are run sequentially using 4 nodes (144 cores).

#!/bin/bash --login

# Slurm job options (name, compute nodes, job time)
#SBATCH --job-name=Test
#SBATCH --time=1:00:00
#SBATCH --exclusive
#SBATCH --nodes=4
#SBATCH --ntasks-per-node=36
#SBATCH --cpus-per-task=1
#SBATCH --output=test.out

# Replace [budget code] below with your budget code (e.g. t01)
#SBATCH --account=t01

# Replace [partition name] below with your partition name (e.g. standard)
#SBATCH --partition=standard

# Replace [QoS name] below with your QoS name (e.g. commercial)
#SBATCH --qos=commercial

# Load any required modules
module load gcc
module load mpt

# Load the HELYX-Core environment v3.5.0 (select version as needed, e.g. 3.5.0)
source /scratch/sw/helyx/v3.5.0/CORE/HELYXcore-3.5.0/platforms/activeBuild.shrc

# Set the number of threads to 1

# Launch HELYX applications in parallel
export myoptions="-parallel"
jobs="helyxHexMesh caseSetup helyxSolve"

for job in `echo $jobs`

   case "$job" in
    *                )   options="$myoptions" ;;

   srun $job $myoptions 2>&1 | tee log/$job.$SLURM_JOB_ID.out


Alternatively, the user can execute most HELYX applications on Cirrus interactively via the GUI by following these simple steps:

  1. Launch HELYX GUI in your local Windows or Linux machine.
  2. Create a client-server connection to Cirrus using the dedicated node provided for this service in the GUI. Enter your Cirrus user login details and the total number of processors to be employed in the cluster for parallel execution.
  3. Use the GUI in the local machine to access the remote file system in Cirrus to load a geometry, create a computational grid, set up a simulation, solve the flow, and post-process the results using the HPC resources available in the cluster. The Slurm scheduling associated with every HELYX job is handled automatically by the client-server.
  4. Visualise the remote data from your local machine, perform changes to the model and complete as many flow simulations in Cirrus as required, all interactively from within the GUI.
  5. Disconnect the client-server at any point during execution, leave a utility or solver running in the cluster, and resume the connection to Cirrus from another client machine to reload an existing case in the GUI when needed.