Getting Started with STAR CCM+ in the Nimbix Cloud
In this article we will show you how to get started using CD-adapco STAR CCM+ in the Nimbix Cloud. CD-adapco and Nimbix have deployed STAR CCM+ on the Nimbix cloud platform, offering the highest performance, most cost effective cloud solution. Nimbix provides unique advantages such as a true high performance computing (HPC) environment (instead of virtualization), fast start-up times and per-minute billing granularity. We have set up the STAR CCM+ application environment for you.
The first step to using the Nimbix Cloud is to create an account. Navigate with browser to https://nacc.nimbix.net. Click Login and when the page refreshes, in the upper right, click Sign Up.
Portable on Demand (POD) Licensing
STAR CCM+ on the Nimbix cloud requires a POD key from CD-adapco. This key should be available in your Steve Portal account. If you don’t have a POD key or don’t know what this means, please contact your CD-adapco representative before proceeding with running STAR CCM+ on the Nimbix cloud.
The Nimbix secure data store is a service called NACC Files. This is where your Nimbix cloud applications primarily read and write data to. You can either move files in and out from 3rd party object storage when you start jobs, or you can access NACC Files directly (via SFTP or as a folder on your desktop using WebDAV over HTTPS).
SFTP provides better performance and is especially helpful when moving large files. You can log in with your NACC username and your NACC account’s API key as the password. The SFTP server address is drop.nimbix.net … you can find your API key in Settings from your username drop-down in the top right hand corner of the NACC portal after you log in. You will need an SFTP client such as FileZilla on most platforms.
If your firewall blocks port 22 outbound or you are looking to drag and drop files between your desktop and NACC, you can use WebDAV. This is a secure protocol that works over HTTPS and is firewall friendly. You don’t need any special client programs, as WebDAV support is already built into your PC or Mac desktop.
On Windows, you just have to use the Map Network Drive functionality in Windows Explorer to connect to NACC Files. Once you’ve done this, the NACC Files folder appears on your desktop as if it were a local folder. The server address is as follows:
When prompted for credentials, enter your NACC user name and API key as the password. Note that you have to specify your NACC user name as part of the server address when connecting, as well as once Windows prompts your credentials.
Here’s how it will look on your Windows Desktop:
The following video demonstrates how to access your NACC Files folder on your Windows desktop:
IMPORTANT NOTE: Windows limits files copied from WebDAV folders to 50MB in size. If you plan on transferring files larger than 50MB, please refer to this article for instructions on how to increase the limit. You can increase the limit to 4.2GB. If you need to transfer files larger than 4.2GB, you must use SFTP.
If you use a Mac, follow the instructions on the Apple knowledge base. Make sure you use the server address as specified above.
If you use a Linux GNOME desktop, follow the instructions for connecting from Nautilus.
Running Interactive STAR CCM+
You can run STAR CCM+ in a 3D graphical environment just like you would from your own desktop. This simplifies the workflow and lets you get started quickly. You can either start with an existing Simulation Database, or create a new one. This works from any device or network, and the 3D environment renders directly in your web browser.
To get started, click the Compute tab and select STAR CCM+ Interactive. The applications are listed alphabetically so you will need to scroll down to find STAR CCM+. Once you click on STAR CCM+ Interactive, click STAR CCM+ to start the workflow. You will be presented with options as in the below screen shots.
If you want to open an existing Simulation Database (which must be a file with extension *.sim), click the gray “folder” icon on the right of the “Simulation Database” entry field. You can find it in your NACC files from there – see above for how to transfer data into the Nimbix cloud.
If you want to start a new Simulation Database, simply leave the “Simulation Database” entry blank.
You must also enter (or paste) your POD license key, exactly as it appears in your Steve Portal. Please note that this is case sensitive, so it is recommended that you copy and paste it, rather than type it in. You should also make sure there are no leading or trailing spaces, as this will cause the license verification to fail. Please note that if you do not enter a POD license key here, you will not be able to use Star CCM+!
Finally, you can run your simulation in parallel across many nodes to improve performance. Each node has 16 cores, so if for example you select 4 nodes, your STAR CCM+ environment will run on 64 cores. Please note that the hourly cost of the job is multiplied by the number of nodes you select as well, as is the “compute time” that is updated in the dashboard.
Once You Confirm your application submission (which shows the actual API call being made to the cloud), you will see a Status message. You will then be directed to your Dashboard.
You will see your job status. Possible Statuses are: Submitted, Processing, Completed, Completed with Error. If you see Completed with Error immediately, it means your POD license key is invalid. Please try again and ensure that you paste the exact license key, case sensitive, with no leading or trailing spaces.
Click on a Processing job to see details and to connect. You may click to view in a web browser. Alternatively, you may use a VNC Client to connect. We support Tiger VNC if you wish to use a VNC client instead of the web browser option (download links provided).
Terminating Interactive Job
You can terminate your sessions from the portal using the Terminate button. Your job will also terminate if you exit the application from within the environment. Your job will not terminate if you close the window or disconnect from your VNC client – you can reconnect and continue your simulation work at a later time. Be sure when your simulation is completed that you have all data written to your /data or My Data folder in the environment before terminating. Finally, be sure not to leave sessions running unnecessarily as this will bill costs to your account.