ECFM-CLEH CO Emissions Model Reference
| Theory | See ECFM-CLEH. | ||
| Provided By | |||
| Example Node Path | |||
| Requires |
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| Properties | Key properties are: Convection, Secondary Gradients, Flow Boundary Diffusion, Pollutant Equilibrium Temperature Offset, Temperature of CO Model Cut Off, CO Relaxation Factor, Inverse CO Production Ratio Factor. See ECFM-CLEH CO Emissions Model Properties. | ||
| Activates | Solvers | See ECFM-CLEH CO Pollutant Solver Properties. | |
| Monitors | CoPollutantPassiveScalar | ||
| Field Functions | CO Pollutant Mass Fraction, Density, and Flame Surface Density. See Field Functions. | ||
ECFM-CLEH CO Emissions Model Properties
- Convection
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In transport equations, you can choose from a range of schemes that calculate the convection term at a cell face. This calculation requires Simcenter STAR-CCM+ to compute the face value of a quantity from the surrounding cell values. The method used for computing this face value has a profound effect on the stability and accuracy of the numerical scheme. For guidance on selecting a convection scheme, see Convective Flux.
- 1st-order: First-order convection scheme.
- 2nd-order: Second-order convection scheme.
- Secondary Gradients
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Neglect or include the boundary secondary gradients for diffusion and/or the interior secondary gradients at mesh faces.
- On: Default value. Solves for interior and boundary types of secondary gradient.
- Off: Does not solve for either type of secondary gradient.
- Interior Only: Solves for the interior secondary gradients only.
- Boundaries Only: Solves for the boundary secondary gradients only.
- Flow Boundary Diffusion
- When activated, this property includes the flow-boundary diffusion fluxes (or viscous fluxes for flow models) as given by Eqn. (899). This property is activated by default.
- Pollutant Equilibrium Temperature Offset
- Offset of temperature that is applied to the unburnt temperature used for equilibrium libraries.
- Temperature of CO Model Cut Off
- Burnt temperature limit under which the CO model is frozen.
- CO Relaxation Temperature
- Relaxation temperature (1200K) in Eqn. (4040).
- CO Relaxation Factor
- Relaxation factor (9000) in Eqn. (4040).
- Inverse CO Production Ratio Factor
- in Eqn. (4036).
ECFM-CLEH CO Pollutant Solver Properties
- Under-Relaxation Factor
- In order to promote convergence, this property is used to under-relax changes of the solution during the iterative process. If residuals show solution divergence or do not decrease, reduce the under-relaxation factor.
- Verbosity
- Allows you to choose how much information Simcenter STAR-CCM+ reports in the Output window while the simulation is running. This property is useful for debugging problems when they occur. The available options are None, Low, and High.
- Solver Frozen
- When On, the solver does not update any quantity during an iteration. It is Off by default. This is a debugging option that can result in non-recoverable errors and wrong solutions due to missing storage. See Finite Volume Solvers Reference for details.
- Reconstruction Frozen
- When On, Simcenter STAR-CCM+ does not update reconstruction gradients with each iteration, but rather uses gradients from the last iteration in which they were updated. Activate Temporary Storage Retained in conjunction with this property. This property is Off by default.
- Reconstruction Zeroed
- When On, the solver sets reconstruction gradients to zero at the next iteration. This action means that face values used for upwinding (Eqn. (905)) and for computing cell gradients (Eqn. (917) and Eqn. (918)) become first-order estimates. This property is Off by default. If you turn this property Off after having it On, the solver recomputes the gradients on the next iteration.
- Temporary Storage Retained
- When On, Simcenter STAR-CCM+ retains additional field data that the solver generates during an iteration. The particular data retained depends on the solver, and becomes available as field functions during subsequent iterations. Off by default.
Field Functions
- CO Pollutant Mass Fraction
- CO mass fraction that is provided by the ECFM-CLEH CO Emissions model.