What initialisation options are accepted by the CFX solver and how can these be accessed?
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For variable field initialisation, the CFX solver accepts four possible options: - Automatic with value This is the most common option and is recommended for most cases. Initial values will be read from an initial values file, if specified, or from an interpolated solution. If neither of these is available, the specified value or CEL expression is used. A value or expression must be specified. - Automatic Initial values will be read from an initial values file, if specified or from an interpolated solution. If neither of these is available, the default initialisation will be applied. A value or expression cannot be specified. - Value The specified value or CEL expression is always used. Note that for restarts, using the 'Value' option will ignore the field in any initial values file. A value or expression must be specified. - Default The solver generates a suitable initial field (see also note 1). A value or expression cannot be specified. INITIALISATION OPTIONS ACCEPTED IN CFX-PRE When setting up a simulation in CFX-Pre, only the reduced subset of 'Automatic' and 'Automatic with Value' options is available (see note 2 for an explanation). HOW TO ACCESS THE FULL SET OF INITIALISATION OPTIONS Probably the easiest way of accessing the full set of options is to edit the definition file with the command file editor (other methods, see note 3). An example of setting the 'Value' option for temperature in an individual domain is shown below: - Open the CFX solver manager - Select 'Tools > Edit Definition File', choosing the definition file you are using for your run - Open the tree: flow/domain/initialisation/initial conditions/temperature you should see something similar to option -> automatic with value temperature -> 300 [K] - Double click on option automatic with value and change the selection to value - Save the modified definition file and restart the run using the previous results file for the initial values file and the modifieddefinition file as the definition file for the run. NOTES 1. For advice on initialisation and information about how the default initial guess is generated, see 'Help > Master Contents > Solver Modelling > Initial Condition Modelling'. 2. The 'Value' option was also available in previous versions of CFX-Pre, but was withdrawn to avoid confusion, because of a number of instances of 'Value' being incorrectly selected instead of 'Automatic with Value' with the result that restarts did not behave as expected. 3. Those familiar with editing command language manually and using the cfx5cmds utility can use this route to access the full set of initialisation options. **** Entered By: dsclarke @ 07/28/2006 10:49 AM **** |
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