### 20.1.1. Basic Settings: Common

#### 20.1.1.1. Advection Scheme

For details, see Advection Scheme Selection in the CFX-Solver Modeling Guide.

#### 20.1.1.2. Turbulence Numerics

The Turbulence Numerics options are `First Order` and `High Resolution`. The `First Order` option uses `Upwind` advection and the `First Order Backward Euler` transient scheme. The `High Resolution` option uses `High Resolution` advection and the `High Resolution` transient scheme.

For details, see Advection Scheme Selection in the CFX-Solver Modeling Guide and Transient Scheme in the CFX-Solver Modeling Guide.

Note: The settings on the Equation Class Settings Tab will override the Turbulence Numerics settings.

#### 20.1.1.3. Convergence Criteria

For details, see Monitoring and Obtaining Convergence in the CFX-Solver Modeling Guide.

- Residual Type: select either `RMS` or `MAX`.

- Residual Target: specify a value for the convergence.

  For details, see Residual Type and Target Levels in the CFX-Solver Modeling Guide.

- Conservation Target: optionally specify the fractional imbalance value. The default value is 0.01.

  For details, see Conservation Target in the CFX-Solver Modeling Guide.

#### 20.1.1.4. Elapsed Wall Clock Time Control

Select the `Maximum Run Time` option if you want to stop your run after a maximum elapsed time (wall clock time).

If you select this option the flow solver will automatically attempt to estimate the time to complete the next timestep or outer loop iteration. The estimated time is the average time that it takes to solve a previous iteration (includes the time to assemble and solve the linear equations, radiation and particle tracking) plus the average time it is taking to write any Standard backup or transient files. The time estimate currently does not include the time used by processes external to the flow solver. This includes mesh refinement, interpolation and FSI with Mechanical.

#### 20.1.1.5. Interrupt Control

Interrupt control conditions are used to specify criteria for stopping a solver run, independent of the convergence criteria (residual target) and specified maximum number of time steps. Interrupt control conditions are specified using logical expressions. These expressions are evaluated by CFX-Solver and are reported in the CFX output file. After executing each iteration (of a steady-state case) or time step (of a transient case), the solver evaluates all internal termination conditions and all user-defined interrupt control conditions. If any of these conditions are true, then solver execution stops and the outcome is written to the CFX output file.

Typically, interrupt control conditions are defined by single-valued logical expressions. However, single-valued mathematical expressions can also be used. In this case, a single-valued mathematical expression is considered to be true if and only if the result of the expression is greater than or equal to 0.5. Otherwise it is deemed to have a value of false. For a discussion on logical expressions, see CFX Expression Language Statements in the CFX Reference Guide.

You should consider setting interrupt control conditions if you expect your case to exhibit transient convergence behavior. For details and an example, see Using Interrupt Control in Cases with Transient Convergence Behavior in the CFX-Solver Modeling Guide.

Note: To prevent a steady-state run from being interrupted before reaching the intended minimum number of iterations, each interrupt condition should include a requirement that the minimum number of iterations has been completed. For example, an interrupt condition could begin with “`aitern>5 &&` ” in order to require that a minimum number of 5 iterations has been reached before the interrupt control condition can evaluate to true.

##### 20.1.1.5.1. List Box

The list box is used to select interrupt control conditions for editing or deletion. Interrupt control conditions can be created or deleted with icons that appear beside the list box.

###### 20.1.1.5.1.1. [Interrupt Condition Name]

Enter a logical expression to specify an interrupt control condition.

#### 20.1.1.6. Junction Box Routine

If you have created any Junction Box Routine objects, select those to include in this Solver run.

For details, see User Junction Box Routines in the CFX-Solver Modeling Guide.

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