Controlling accuracy of the numerical integration with quadrature settings (Acoustics BEM)

You control the accuracy of the numerical integration scheme by specifying the Gauss quadrature, which is the number of Gauss points that control the numerical integration.

You can select from one to five Gauss points in one direction for the numerical evaluation of integrals for three different regions: near field, medium field, and far field.

The boundary elements in near, middle, and far field regions are defined by the ratio D/L where:

• D = Distance between the two boundary element centers

• L = Average element edge length

You can set the two parameters (a = Near-mid and b = Mid-far) to define the regions as follows:

• For Near-Mid Field Boundary Ratio (a), a >= 0

• For Mid-Far Field Boundary Ratio (b), 0 <= a <= b

• For the Near Field Quadrature if 0 <= D/L <= a, the two elements or faces are in the near field of each other

• For the Middle Field Quadrature if a < D/L <= b, the two elements or faces are in the medium field of each other

• For the Far Field Quadrature if D/L > b, the two elements or faces are in the far field of each other

Solver quality parameters

You use Accuracy Level to select Fine, Standard, Coarse, or Custom solution quality parameters. When you enter the field values manually using Custom the field values can be a maximum of 2.

Note:

These options are available for all BEM solvers, except for the Indirect BEM acoustic or vibro-acoustic solvers.

Default Quadrature Quality Parameters	Fine	Standard	Coarse
Distance Near-Mid Field	2	2	2
Distance Mid-Far Field	5	30	5
Order Near Field	2	2	2
Order Mid Field	2	2	2
Order Far Field	2	1	1

Normally, the quadrature should be higher in the near region.

You can also set the quadrature using the Custom option. When you enter the field values manually using Custom the field values can be a maximum of 2.

Note:

Increasing the Gauss quadrature order will produce more accurate results, but can take longer to solve. Using the Fine setting can be costly in terms of computer resources and solution time.

Increasing the quadrature may be necessary, however, when the problem is numerically difficult (for example, a fluid region that is tightly bounded by two opposed surfaces, there are small holes in the boundary mesh, or there are sound sources near the mesh surface).

The maximum quadrature values for any solution are limited to 2 2 2.

Where do I find it?

Application	Pre/Post
Prerequisites	A Simulation file as the work part and displayed partSimcenter 3D Acoustics BEM as the specified solverDirect Acoustic, Indirect Acoustic, or Indirect Vibro-Acoustic as the specified analysis type
Command Finder	Solution
Simulation Navigator	Right-click the Solution→Edit
Location in dialog box	Quadrature group

Quick links

Command reference

Pre/Post video examples

Bulk Entry Descriptions

Simcenter 3D tutorials

Browse Simcenter 3D help by product area

Controlling accuracy of the numerical integration with quadrature settings (Acoustics BEM), Simcenter 3D 2021.1 Series

© 2020 Siemens

window.mainLanguage="en_US"

window.delivId=""

window.projectId=""

MathJax.Hub.Config({ TeX: { extensions: ["autoload-all.js"] }, tex2jax: { displayMath: [ ] }, "SVG": { scale: 125 } });