Radiation Heat Transfer and Environmental Heating

RadCAD® computes radiation exchange factors within the thermal model and with the environment using both solar and infrared spectra. It is a module available for use with Thermal Desktop® or even as a standalone product, and it operates in the same CAD environment.

Fast and Accurate Thermal Radiation Analysis

An ultra-fast, oct-tree accelerated Monte-Carlo ray tracing algorithm is used by RadCAD to compute radiation exchange factors and view factors. Innovations by C&R Technologies to the ray tracing process have resulted in an extremely efficient thermal radiation software tool.

Using finite difference "conics" (simple geometric objects) or curved finite elements from TD Direct®, RadCAD can accurately model diffuse or specular reflections and transmissive surfaces regardless of node density. The needs of the thermal solution dictate the number of nodes, not the accuracy requirements of the radiation.

RadCAD makes use of user-defined databases of optical properties. Each surface coating defines absorptivity, transmissivity, and reflectivity along with specularity in both the solar and infrared wavelength regimes. These properties can be defined versus incident angle or even with wavelength dependence. 

Articulated Geometry: Moving Parts

RadCAD is fully equipped to handle moving geometry. Fully user-definable Trackers allow part of the geometry to follow the sun, nadir, or any star. These Trackers can be nested to operate on multiple axes.

More generic movement can be accomplished using Assemblies, which allow any part of the geometry to rotate and/or translate in unlimited nested configurations. Because they are general purpose, Assemblies can be used to model anything from deploying a multi-jointed antenna to opening a door of a furnace.

Radiation Environments

The definition of the environment can be one of the most challenging parts of a thermal analysis, but RadCAD makes it easy. Because the sun plays such a critical part in most environments, even for stationary components on the Earth, the environments within RadCAD are called Orbits. These Orbits define the appropriate diffuse and direct solar, albedo, and ground IR heating for everything from objects located in a window to ships, aircraft, spacecraft, and even rovers on distant planets.

Thermal Radiation Software Features

  • CAD drawing methods and high-level RadCAD surfaces including snap-on methods that use CAD drawings as "scaffolding"
  • Variable geometry through the use of articulators (assemblies and trackers)
  • Solve for form factors, radiation exchange factors, or absorbed fluxes
  • Choice of solution methods: accelerated Monte Carlo ray tracing (MCRT) or progressive radiosity
  • Proprietary advances in Oct Cell technology for amazingly fast computations
  • True curved geometric surfaces
  • Specular and Diffuse surfaces
  • Angle-dependent and wavelength-dependent surface properties
  • Supports both grey and non-grey radiation calculations
  • Full orbital plotting package with both basic and Keplerian input
  • Analysis groups offer significant speed savings
  • Optical Property Aliases help in database management
  • Refraction capabilities for transparent specular surfaces
  • Automatic Oct Cell optimization for determining best subdivision and surfaces per cell criteria
  • Vector List Orbit definition for modeling trajectory orbits
  • Celestial Coordinate System orbit definition
  • Arbitrary source input for modeling IR/Solar Lamps
  • Fast-spinning surfaces
  • Symmetry planes and mirror surfaces
  • Automatic restart determination
  • Free Molecular Heating (FMH) algorithms
  • Quick checks to aid in radiation model debugging
  • Postprocessing (view factors, RADKs, fluxes, SINDA temperatures, etc.)

Import and Export Capabilities

  • TRASYS import and export
  • Nevada import
  • STEP-TAS model translation available through a third-party app
  • IDEAS FD import
  • TSS import and export