Radiation Enclosure only supports 2D (Include 2D Axisym Edge) or 3D target. This load is used when the view factor or exchange factor is unknown. The view factor or exchange factor is calculated by external radiation codes, such as NEVADA, THERMICA, TRASYS or TSS.

Currently MSC Sinda for Patran only supports one enclosure. Even if different enclosure IDs are entered, MSC Sinda for Patran will treat them as one big enclosure.

About the edge radiation, the Radiation Enclosure load only supports 2D Axisym/Edge, because the external radiation codes only accept surface radiation. None of the above radiation codes can support edge radiation analysis (2D model radiation). MSC Sinda for Patran supports the 2D axis symmetric model because it can be converted into 3D radiation model by the translator.

When input data option is selected, emissivity is usually for infrared wave band, and absorptivity is usually for visible light wave band (such as sunlight). Please note they are not for the same wave band. The absorptivity is required for orbital heating of a satellite or spaceship. The view factor or exchange factor calculation, however, does not require absorptivity (except THERMICA). Actually, the infrared absorptivity is the same as emisssivity, therefore no extra data input is needed.

Radiation enclosure has two options: the small facets method and the super element method. The small facets method is the traditional way of FEM modelers to calculate radiation view factors. The super element method is one of our two unique methods for speeding up radiation calculation. When the super element option is chosen, all the facets in the application region will be treated as one radiation node which is called a radiation super element. This makes the radiation analysis much faster and more efficient. More details on super element and primitive methods will be discussed later in this user’s guide.

Radiation super element is not limited to one surface or one solid face. It is usually used for those places where the overall temperature level is more important or sensitive for radiation accuracy, rather than the temperature gradient. For those positions where the temperature gradient is very important, small facets or primitives method is recommended.

When the small facets method is selected, the radiation enclosure supports spatial functions. The super element option does not support spatial functions.