### 3.2.11. Epsilon (Turbulence Eddy Dissipation)

#### 3.2.11.1. Automatic Values

The default turbulence eddy dissipation is calculated as:

| (3–2)

where:

is a non-dimensional constant

is the turbulent kinetic energy

is the kinematic viscosity

is the eddy viscosity ratio, which is set to 10 by default

#### 3.2.11.2. Recommended Values

Unless you have information about the turbulence eddy dissipation for your application, use the `Automatic` initial guess.

#### 3.2.11.3. Manual Specification

Turbulence eddy dissipation can be specified as a function of:

- `Omega` (that is, turbulence eddy frequency)

- `Eddy Length Scale`

  | (3–3)

- `Eddy Viscosity Ratio`

  | (3–4)

Turbulence eddy dissipation can also be specified directly as a CEL expression.

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