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- 资料来源：ICEM CFD Help Manual

密度盒(Mesh Density):

密度盒选项允许用户创建或控制一块区域，在该多面体(或二维多边形)区域中可指定局部最大网格单元尺寸。这一功能对于那些不与任何几何体相邻的体积域网格的细分非常有用，例如汽车尾流区。可以在一个密度盒中再创建另一个，也可以将两个密度盒交叉。

如果它们重叠或交叉，较小的尺寸网格将取代较大的网格尺寸。密度盒不一定要完全包含在计算域中，它可以是部分的与几何体相交或者是部分的包含于计算域内。

注意：密度盒区域并不是几何的part，而且网格节点也不受约束于密度区域。

这一功能仅仅在Tetra,Cartesian及Patch Independent表面网格方法中才有效。

关于选项的解释：

1、Name

指定密度盒的名称。

2、Size

指定密度盒内局部最大尺寸。该尺寸将受Global Scale Factor的影响。

3、Ratio

指定密度盒周围的四面体增长率。

4、Width

对于密度盒，这指定了远离密度盒边界的恒定的膨胀率的层数(N)，其应该具有恒定的扩展比率。第N+1层的四面体尺寸为Size与Ratio的乘积。

对于线和点密度，受密度盒影响的区域的半径为Size与Width的乘积。

5、Density Location

有以下两种方式来定义密度盒：From Points：通过一个或多个点定义密度箱边界。

From Entity Bounds：选择对象边界定义密度箱。

附上ICEM CFD Help Manual原文：

Create Mesh Density

The Create Mesh Density option allows you to create or manipulate a density region.

This is a polyhedral (or polygonal for 2D) zone in which one can prescribe a local maximum element size. This is useful for refining the mesh in a volumetric zone that is not adjacent to any geometry, for example, in the wake region of a vehicle. You can have density regions within one another, or partially intersecting one another.

A smaller mesh size within one density region will supersede that of a greater mesh size if they overlap or intersect. The density region does not have to be totally within the volumetric domain, but can intersect geometry and partially be within the dead zone.

Note: The density region is not part of the geometry, and mesh nodes are not constrained to the density region.

Note: This affects only Tetra, Cartesian, and Patch Independent surface mesh methods.

Name

specifies the name for the density region. Enter an appropriate name or accept the default.

Size

specifies the local maximum mesh size that can occur within the density region. This will be multiplied by the Global Scale Factor.

Ratio

specifies the tetra growth ratio away from the density region.

Width

For a density region, this specifies the number of layers (N) of the specified element size away from the boundary of the density region that should have a constant expansion ratio. The layer N + 1 will have a tetra size of the Size value multiplied by the Ratio.

For line and point densities, the Size value multiplied by the Width is the radius of the region that the density region influences.

Density Location

The location of the density region can be defined in the following ways:From Points

Select one or more points to define the boundaries of the density region.From Entity Bounds

Select an entity to define a density region within its boundaries.