Radiation Primitives supports only 2D or 3D target. This load is almost the same as radiation enclosure, except it uses real curved surfaces instead of flat small facets. The Primitive surface or primitive solid is a new development from MSC. In Patran, this new geometry is named P-Shape. The parameters of primitives can be read out from Patran db. The Radiation primitives load only applies to primitive surfaces or primitive solids. If some ordinary surfaces or solid faces are included in the application region, the small facets method will be used for these surfaces.

There are eight primitive surfaces and two primitive solids. The eight primitive surfaces include rectangular, quadrilateral, triangle, disc, cylinder, cone, sphere, and paraboloid. The two primitive solids include a six-sided box and a five-sided box. MSC Sinda for Patran does not yet support solid primitives for radiation.

Primitives can be meshed like other ordinary surfaces or solids. This mesh will be used to calculate thermal conductors. It can be called a conduction mesh or a FEM mesh. According to the A, B mesh input, a synthetic mesh will be created on the same primitives, and used for radiation analysis. It is called AB mesh. Therefore, the radiation analysis is based on real curved AB meshed surfaces instead of flat small facets.

The AB mesh does not have to match, or be consistent with the conduction mesh. Somewhat like contact load, a similar method is used to automatically distribute the radiation conductors between the AB mesh and conduction mesh. More details on primitives and primitive radiation will be introduced in chapter 10 of this user’s guide.

Radiation primitives do not support spatial fields. Coating or MLI materials can be referenced which may cause arithmetic nodes in the MSC Sinda input file.

The AB mesh library illustrates the primitive parameters and the A and B directions.

A primitive load application region may consist of many primitive surfaces, even ordinary surfaces. The MSC Sinda for Patran translator will automatically separate each primitive or ordinary surface. The primitive surface will be meshed into real curved facets according to AB mesh input, while ordinary surfaces will be converted into small flat facets.

Please reference chapter 10: Super Element and Primitives for more details.