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Thermal-Flow
Contains general thermal and flow solver related documentation, such as the verification test cases, monthly critical fixes, DMP guide, and knowledge base articles.
Thermal and flow DMP guide
Describes the general workflow for executing the simulation jobs using distributed memory parallel processing on clusters and the scheduler-dependent files required to submit the jobs to the scheduler.
A host file
The scheduler generates the mayampi.hosts file at runtime before running the jobs in parallel. This file includes a list of cluster nodes that will execute the jobs.

Thermal-Flow
Contains general thermal and flow solver related documentation, such as the verification test cases, monthly critical fixes, DMP guide, and knowledge base articles.
- TMG thermal-flow solvers
  Maya HTT develops and maintains a thermal solver and a flow solver, which are combined into the TMG thermal-flow solvers. These solvers are included and distributed with Simcenter 3D, NX, and Simcenter Femap. Older versions of TMG thermal-flow solvers are also included in NX I-deas.
- Thermal and flow verification test cases
  Contains verification test cases for the thermal and flow solvers.
- Monthly critical fixes
  Lists critical bugs that are fixed monthly for the thermal and flow solvers.
- TMG Executive Menu
  TMG Executive Menu is a standalone application that lets you execute processes on thermal-flow files and solutions independently of Simcenter 3D or Simcenter Femap.
- Thermal and flow DMP guide
  Describes the general workflow for executing the simulation jobs using distributed memory parallel processing on clusters and the scheduler-dependent files required to submit the jobs to the scheduler.
  - Parallel processing on a cluster
    Using distributed memory architecture, the TMG thermal-flow solvers support high performance computing (HPC) for large models on a multi-node cluster. These solvers use Distributed Memory Parallel (DMP) processing based on domain decomposition and the message passing interface (MPI).
  - Executing DMP simulations
    The following workflow describes running DMP simulations. The TMG thermal-flow solvers installation, TMG Executive Menu, and required scheduler dependent files must be all accessible by the nodes in the cluster.
  - Submit a DMP simulation
    You submit a DMP simulation from the TMG Executive Menu, which is on a machine that has access to the solution input XML file and the scheduler. It is preferable to use the head node of the cluster, which is accessible from all the nodes.
  - Scheduler dependent files
    TMG Executive Menu requires multiple scheduler dependent files to communicate with a scheduler.
  - A host file
    The scheduler generates the mayampi.hosts file at runtime before running the jobs in parallel. This file includes a list of cluster nodes that will execute the jobs.
- Thermal-flow data exchange files
  The thermal and flow solvers in Simcenter 3D and Simcenter Femap create multiple thermal-flow data exchange files described on the following page.

A host file

The scheduler generates the mayampi.hosts file at runtime before running the jobs in parallel. This file includes a list of cluster nodes that will execute the jobs.

The following is an example of the host file format, which TMG thermal-flow solversexpect, to execute a simulation in parallel on six processes of two nodes. Each node will run three processes:

tmgnode1
tmgnode1
tmgnode1
tmgnode2
tmgnode2
tmgnode2

Example of a host file for the SGE scheduler

Each scheduler controls the number and names of the nodes that will run the simulation. For example, the SGE scheduler stores this information in a file using the parallel environment variable pe_hostfile. The concept of a parallel environment (pe) is specific to the SGE scheduler. In this example, the parallel environment under which the job are submitted is defined as monitor. The SGE scheduler lets you define a start procedure, which occurs the moment before launching the job in the queue. In the parallel environment, the start procedure is defined as:

/shared_nfs/scripts/create_hostfile.sh $pe_hostfile

Next, the following script creates the mayampi.hosts file in the run directory:

#!/bin/bash
#
#  * $1 is the SGE host file name
#
awk '{for (i=0;i<$2;i++) print $1}' $1 > $SGE_O_WORKDIR/mayampi.hosts