# SpiralAnularMeshGenerator

## Overview

This MeshGenerator object allows the user to create an annular mesh. The nodes are located on several concentric rings, and the elements are of type Tri3 (they can be Tri6 if the user changes the value of the use_tri6 parameter to true).

The user can choose the inner and outer radii, the number of rings, and finally the number of nodes on each ring. Given all these parameters, the radial bias will be computed automatically.

## Input Parameters

• num_ringsThe number of rings.

C++ Type:unsigned int

Options:

Description:The number of rings.

• nodes_per_ringNumber of nodes on each ring.

C++ Type:unsigned int

Options:

Description:Number of nodes on each ring.

• outer_radiusThe size of the outer circle. Logically, it has to be greater than inner_radius

C++ Type:double

Options:

Description:The size of the outer circle. Logically, it has to be greater than inner_radius

• inner_radiusThe size of the inner circle.

C++ Type:double

Options:

Description:The size of the inner circle.

### Required Parameters

• exterior_bid2The boundary id to use for the exterior (outer circle)

Default:2

C++ Type:short

Options:

Description:The boundary id to use for the exterior (outer circle)

• initial_delta_rWidth of the initial layer of elements around the cylinder.This number should be approximately 2 * pi * inner_radius / nodes_per_ring to ensure that the initial layer of elements is almost equilateral

C++ Type:double

Options:

Description:Width of the initial layer of elements around the cylinder.This number should be approximately 2 * pi * inner_radius / nodes_per_ring to ensure that the initial layer of elements is almost equilateral

• use_tri6FalseGenerate mesh of TRI6 elements instead of TRI3 elements.

Default:False

C++ Type:bool

Options:

Description:Generate mesh of TRI6 elements instead of TRI3 elements.

• cylinder_bid1The boundary id to use for the cylinder (inner circle)

Default:1

C++ Type:short

Options:

Description:The boundary id to use for the cylinder (inner circle)

### 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.