33.3.24 Autoignition Model Dialog Box

The Autoignition Model dialog box allows you to set the parameters related to the Knock Model or the Ignition Delay Model. See Chapter  20 for details.

Controls

Model   contains options to disable or enable models.

Off   disables the model.

Knock Model   enables the knock model. With the Premixed Combustion or Partially Premixed Combustion models selected, only the Knock Model can be turned on.

Ignition Delay Model   enables the ignition delay model.

Options   contains two correlation options that exist with each model.

Douaud   option is used for knock in spark ignition engines. The modeling parameters that are specified in the GUI for this option are the Pre Exponential, Pressure Exponent, Activation Temperature, Octane Number, and Octane Exponent ( this equation in the separate Theory Guide).

Generalized   enables generalized correlation described by this equation in the separate Theory Guide. It requires the same parameters as in the ignition delay model.

Hardenburg   enables Hardenburg correlation, which is used for heavy-duty diesel engines. This option is activated only for the ignition delay model.

Model Parameters   contains parameters related to the selected model.
See Section  20.2.1 for the details about the parameters in this dialog box.

Pre-Exponential   see this equation and this equation in the separate Theory Guide.

Activation Temperature   see this equation in the separate Theory Guide.

Pressure Exponent   see this equation and this equation in the separate Theory Guide.

Octane Number   see this equation and this equation in the separate Theory Guide.

Octane Number Exponent   see this equation and this equation in the separate Theory Guide).

Activation Energy   see this equation and this equation in the separate Theory Guide.

Temperature Exponent   see this equation in the separate Theory Guide.

RPM Exponent   see this equation in the separate Theory Guide.

Equivalence Ratio Exponent   see this equation in the separate Theory Guide.

Options   contains two correlation options that exist with this model.

Douaud   enables Douaud correlation ( this equation in the separate Theory Guide) used for knock in SI engines.

Generalized   option ( this equation in the separate Theory Guide) in the knock model require the same parameters as in the ignition delay model.