# LevelSetOlssonVortex

A function for creating vortex velocity fields for level set equation benchmark problems.

One of the most often utilized benchmark problems for the level set equation involve a vortex velocity field in two-dimensions that result in a full reversal of the advected variable after some time. The LevelSetOlssonVortex provides the velocity in the x and y direction ( and ) defined by Olsson and Kreiss (2005) as:

(1)

There are two methods defined for reversing the velocity direction ("instantenous" and "cosine"). The former simply switches the sine of the velocity at mid-point of the provided reversal time. The later applies a cosine multiplier so that the reversal is smooth.

## Example Input Syntax


[Functions]
[./vel_x_func]
type = LevelSetOlssonVortex
component = x
[../]
[./vel_y_func]
type = LevelSetOlssonVortex
component = y
[../]
[]
(modules/level_set/test/tests/functions/olsson_vortex/olsson_vortex.i)

## Input Parameters

• componentThe component of velocity to return.

C++ Type:MooseEnum

Options:x y z

Description:The component of velocity to return.

### Required Parameters

• reverse_time2Total time for complete vortex reversal.

Default:2

C++ Type:double

Options:

Description:Total time for complete vortex reversal.

• reverse_typeinstantaneousThe time of reversal to enforce (instantaneous or cosine).

Default:instantaneous

C++ Type:MooseEnum

Options:instantaneous cosine

Description:The time of reversal to enforce (instantaneous or cosine).

### Optional Parameters

• control_tagsAdds user-defined labels for accessing object parameters via control logic.

C++ Type:std::vector

Options:

Description:Adds user-defined labels for accessing object parameters via control logic.

• enableTrueSet the enabled status of the MooseObject.

Default:True

C++ Type:bool

Options:

Description:Set the enabled status of the MooseObject.