### 3.3.3. Using Multiple Files to Provide Initial Conditions

You might want to use more than one Initial Values Files to provide initial conditions for your new run. This is most likely to be applicable if you have simulated multiple parts of a geometry (for example, multiple stages of a rotating machine) separately, and then want to use these existing results to initialize a simulation of the full geometry (for example, the full rotating machine). Another example would be where you run a transient simulation where at some point during the calculation, a valve opens and connects two previously-separate enclosures: you could perform a lengthy transient run simulating the complex physics in one part of the geometry up to the time where the valve opens, perform a quick steady-state simulation of the less-interesting conditions in the other part of the geometry, and then use both existing results files to provide the initial conditions for the run of the full geometry after the valve opens.

Multiple Initial Values Files can be specified by creating more than one Initial Values object on any of the panels where you can specify an Initial Values File.

The Continue History From check box setting (see above) can only be applied to one of the Initial Values Files selected. The monitor data, particle positions and tracks, and iteration/timestep counter will be read from that file. Particle positions and tracks and monitor data from the other file(s) will be ignored.

It is recommended that where practical, separate domains are created in the new CFX-Solver Input file for the region of space occupied by each of the Initial Values Files (that is, each new domain only overlaps with the geometry from one of the Initial Values Files), particularly when the Initial Values Files do not have identical physics and material names. This is because the CFX-Interpolator interpolates results domain by domain, and if each domain only picks up initial values from one Initial Values File, then the resulting mapping of variables is simpler. Where it is not possible to have one or more separate new domains for each existing Initial Values File, then it is recommended that you read the section Interpolating from Multiple Files to be aware of the limitations.

Where your Initial Values Files have geometry that overlap or do not fully cover the geometry of the new CFX-Solver Input file, it is recommend that you read the section Interpolating from Multiple Files to be aware of how the CFX-Interpolator calculates the initial values for these cases.

Release 18.2 - © ANSYS, Inc. All rights reserved.