## 9.3. Eddy Dissipation Model

The Eddy Dissipation model is best applied to turbulent flows when the chemical reaction rate is fast relative to the transport processes in the flow. There is no kinetic control of the reaction process. Thus, ignition and processes where chemical kinetics may limit reaction rate may be poorly predicted.

By default, for the Eddy Dissipation model it is sufficient that fuel and oxidant be available in the control volume for combustion to occur. If the product limiter is enabled, by setting the Eddy Dissipation Coefficient B parameter to positive, then products must also be available. For details, see Eddy Dissipation Model Coefficient A/B. However, combustion products may not always be specified as an input. In this case, products could not form unless they are introduced into the domain. Assuming the problem is one in which a stable flame may be established, initial specification of products within the domain should be sufficient to start and maintain combustion. However, if the combustion is difficult to maintain, it may be necessary to introduce a small fraction of products at an inlet.

The following topics will be discussed:

- Fluid Models

- Initialization

- Solver Parameters

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