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The following parameters must be specified on the Advanced tab of the Define Altair HyperXtrude Analysis Parameters dialog:



Relaxation Factor – Velocity

Weighting factor for velocity relaxation. See Relaxation Factors.

Relaxation Factor – Temperature

Weighting factor for temperature relaxation. See Relaxation Factors.

Strain Calculation Method

If strain is specified on Inflow/SolidFluidInterface boundary, this parameter is automatically set to Galerkin. This default value can be overridden with any of the other acceptable values.

Memory for Solver

Used to specify in-core/out-of-core RAM memory usage by the linear equation solver. The default is 128 MB. If N is set to 0, the solver will use only out-of-core memory. N can be set to -1 to force all in-core calculations by the solver. In this case, the machine should have enough extra RAM to load the code and the database.        

Reserved Memory Size

This parameter is used to determine the amount of memory needed by HyperXtrude.

This parameter is valid only for 64-bit Linux machines and it is ignored for all other platforms. There are two parameters that deal with allocation of memory: MemoryForSolver, and ReservedMemorySize.  Of these, MemoryForSolver is also included in ReservedMemorySize. Therefore, MemoryForSolver should be less than ReservedMemorySize.

For example, if the MemoryForSolver is 512 MB and ReservedMemorySize is 2048 MB,   the 2048 MB includes the 512 MB in its count, which means, after taking 512 MB for the linear solver, only 1536 MB is available for the remaining solver needs. This is a fixed amount and cannot grow dynamically during the run. However, even if you allocate only 512 MB for MemoryForSolver, that can expand without affecting the rest during run time. So, if you want increase the size, leave the MemoryForSolver to the default value of 512 MB in the HyperXtrude interface and increase only the ReservedMemorySize.

Because ReservedMemorySize is specific for 64-bit machines, it is usually not a problem to overestimate this parameter. It must be set to less than the total amount of swap space, but it can be safely set even higher than amount of physical RAM. The HyperXtrude Interface will try to estimate this value based on the size of the mesh. However, this estimate is based on thumb rule and sometimes may not be adequate. Depending on the computing capacity you have, you can increase this number in the Tcl file. In addition to the value specified in ReservedMemorySize, HyperXtrude uses some additional memory for its database and post-processing (if used). The size of the database will be approximately the size of the autosave file.

Note: if you make the ReservedMemorySize very large without reason, you will end up monopolizing the machine (thereby denying memory to other processes) or PBS servers may place your job far behind in the queue.

Type: Integer 

Minimum: Should be greater than 1024, or at least 1.67 times the MemoryForSolver.

Maximum: depends on the size of the RAM and swap space

Relaxation Factor – Pressure

Weighting factor for pressure relaxation. See Relaxation Factors.

Relaxation Factor – Strain

Weighting factor for strain relaxation. See Relaxation Factors.

H3D File Save Frequency

When performing a transient analysis, you can avoid saving the solution in the H3D file at every time step to reduce the file size. Use this parameter to specify the time interval to be used for saving the file. For example, if the frequency is 4, the solution will be saved at every fourth step (4, 8, 12, etc.) The default value is 1.



See Also:

Process Parameters