32.2 Starting Parallel ANSYS FLUENT Using FLUENT Launcher

Whether you start ANSYS FLUENT either from the Linux/UNIX or Windows command line with no arguments, from the Windows Programs menu, or from the Windows desktop, FLUENT Launcher will appear (see Section  1.1.2), where you can specify the dimensionality of the problem (2D or 3D), as well as other options (e.g., whether you want a single-precision or double-precision calculation).

Parallel calculation options can be set up by selecting Parallel under Processing Options in FLUENT Launcher. Once you select the Parallel option, you can also specify the number of processes using the Number of Processes field. Activating the Parallel option enables the Parallel Settings tab (visible when you select the Show Additional Options button). The Parallel Settings tab allows you to specify settings for running ANSYS FLUENT in parallel.

Figure 32.2.1: The Parallel Settings Tab of FLUENT Launcher

• Specify the interconnect or system in the Interconnects drop-down list. The default setting is recommended.For a symmetric multi-processor (SMP) system, the default setting uses shared memory for communication.

  If you prefer to select a specific interconnect, you can choose either ethernet, myrinet, or infiniband.For more information about these interconnects, see Table  32.3.1, Table  32.3.2, and Table  32.3.3.

• Specify the type of message passing interface (MPI) you require for the parallel computations in the MPI Types field. The list of MPI types varies depending on the selected release and the selected architecture. There are several options, based on the operating system of the parallel cluster. For more information about the available MPI types, see Tables  32.3.1- 32.3.2.

  It is your responsibility to make sure the interconnects and the MPI types are compatible. If incompatible inputs are used, FLUENT Launcher resorts to using the default values.

• (Linux/UNIX Only) Specify either RSH (remote shell client) or SSH (secure shell client) under Remote Spawn Command. For more information about setting up your remote shell clients and secure shell clients, see Section  32.4.2.

• Specify the type of parallel calculation under Run Types:
  • Select Shared Memory on Local Machine if the parallel calculations are performed by sharing memory allocations on your local machine.

  • Select Distributed Memory on a Cluster if the parallel calculations will be distributed among several machines.

    You can select Machine Names and enter the machine names directly into the text field. Machine names can be separated either by a comma or a space. This is not recommended for a long list of machine names.

    Alternatively, you can select File Containing Machine Names to specify a hosts file (a file that contains the machine names), or you can use the button to browse for a hosts file. To edit an existing hosts file, click the button.

• Specify if you would like to cache the password for the HP-MPI or not.

  Select the Cache HP-MPI Password option if you would like to save the required password to use the HP MPI type.

• Select Use Microsoft Job Scheduler (Windows) or Use Job Scheduler (Linux/UNIX) under Options if the parallel calculations are to be performed using a designated Job Scheduler (see Section  32.2.1). This also enables the Scheduler tab of FLUENT Launcher.