How do I run "Fluent" interactively?

How do I run "Fluent" interactively?

The following instructions assume that you are a member of the Unix group "fluent". The instructions in this section are only useful if you want to use the graphical user interface of Fluent, for instance to setup a job, or pre- and post-process a production job. If you want to run a production job, please refer to to instructions on how to start a Fluent batch job (see ).

The Fluent program is started by setting a system variables FLUENT_ARCH, FLUENT_INC, and FLUENT_LICENSE_FILE to let the system know about the computing platform employed (UltraSparc), the directory where the software resides and the license file used, respectively. It is also useful to include the directory with the Fluent executable in your path. Here is the command sequences to do all this:

	(for csh)
	setenv FLUENT_ARCH ultra
	setenv FLUENT_INC /opt/fluent/Fluent.Inc
	setenv FLUENT_LICENSE_FILE $FLUENT_INC/license/license.dat
	setenv PATH $FLUENT_INC/bin:$PATH

	(for ksh, bash, etc)
	FLUENT_ARCH=ultra; export FLUENT_ARCH
	FLUENT_INC=/opt/fluent/Fluent.Inc; export FLUENT_INC
	FLUENT_LICENSE_FILE=$FLUENT_INC/license/license.dat
	export FLUENT_LICENSE_FILE
	PATH=$FLUENT_INC/bin:$PATH; export PATH
        

These settings apply for the 32-bit version of Fluent, which is the default. Since our Sunfires are 64-bit machines, and Solaris 10 is a 64-bit operating system, there is also a Fluent version that uses a 64-bit address space. If you want to use the 64-bit version, you need to specify ultra_64 for FLUENT_ARCH. Everything else remains the same.

There is a simple alternative for setting up your environment for the usage of Fluent: you can leave the above commands to usepackage and simply type

		use fluent (32-bit, default), or
		use fluent_64bit (64-bit)

after login. This will automatically issue the above commands. You can also include the use command in your setup file (.login or .profile) if you are using fluent regularly.

Then you invoke a graphical user interface by typing

	fluent

Since you are usually working from an external console, it might be necessary to set the DISPLAY environment variable to ip_address:0, where ip_address is the IP address of your local console. It might also be recommendable to write these commands into a short script file and execute that.

The first choice you have to make is if you are solving a two- or a three-dimensional problem, and if you want to do so in single or double precision. You can do so by typing "2d", "3d", "2ddp", or "3ddp", respectively. All further commands can be typed in "by hand", or they can be issued by clicking on the toolbar on the top of the GUI and selecting the appropriate sub-choices. Note that if you want to type a command yourself, and you do not know what your choices are, simply pressing the Enter key will give you a list of applicable commands.

It is , of course, impossible to even outline how to use Fluent appropriately. In many cases, you will want to read in a "case file", which has all the required information to describe the system you want to simulate. Such case files have the file extension .cas. Load them by issuing the /file/read-case command or selecting the corresponding menu-commands in the GUI. You can now check and display the grid, specify boundary conditions and material properties, initialize the flow, and perform calculations.

Results are usually saved by the /file/write-case-data command. During an interactive session, it is sometimes a good idea to keep a "journal file" which records all commands that you have typed in or issued via the GUI. This journal file can later be used as a template for a batch command file. Define the journal file with the "/file/start-journal" command.

The usage of Fluent is documented in html format on machines where Fluent is installed. On our system you can access this documentation by calling a Firefox web browser (type firefox &), and pointing it to

file:///opt/fluent/Fluent.Inc/help/index.htm

This documentation is also available in pdf format in

/opt/fluent/Fluent.Inc/help/pdf

Note that the documentation is only accessible if you are signed up as a Fluent user on our system.