LMS Samcef Amaryllis

Model the thermal response of charring ablators during atmospheric re-entry or fire conditions, including char swell and conduction-radiation coupling

When composite structures are subjected to high heat loads, they will undergo degradation. LMS Samtech Samcef Amaryllis allows you to model the thermal response of charring materials in general and charring ablators specifically. You can model charring using Arrhenius-type laws of varying levels of complexity; ablation can include phase change ablation, mechanical erosion and chemical ablation. The ablation will result in a surface recession that is taken into account via a mesh deformation algorithm.

The element library consists of elements that model conduction, gas diffusion and charring. For the charring of the material, you can use models of increasing complexity – from a single Arrhenius law to a user defined multi-species law. All material properties can depend (nonlinearly) on temperature, pressure and density (charring), and the conductivity can be anisotropic.

When the composite material is lightweight (porous), you need to model the heat transfer by radiation and even conduction-radiation coupling. The conduction-radiation coupling is implemented using a volume ray tracing algorithm. Due to the outgassing of pyrolysis (charring) gasses, the boundary conditions will be modified and interact with the ablation boundary condition – indispensable for atmospheric re-entry applications. For ablation applications, specialized functions are available that measure the evolving mass of the structure and temperature on the deforming mesh.

LMS Samcef Amaryllis is an integral part of LMS Samcef Thermal Analysis, thus sharing parallel nonlinear solver technology and the automatic time-step algorithm. In addition, all functions available in the thermal response solver can be used in LMS Samcef Amaryllis including surface radiation modeling, thermal contact and the strong integration with LMS Samcef Nonlinear Structural Analysis.

The thermomechanical coupling is necessary when you need to model char swell (or intumescence), where the conductive path is increased due to swelling. In studying the behavior of composites that are subjected to fire, the coupled solution becomes indispensable because the degradation of the composite is mechanical and thermal in nature.

LMS Samcef Amaryllis Capabilities

LMS Samcef Amaryllis Capabilities

LMS Samcef Amaryllis provides you with these features:

  • Variety of boundary conditions, from a simple imposed flux to complex interactions
  • Thermal contact algorithms that consider deformation of the mesh from surface ablation
  • Postprocessing, options that list and display temperatures, conductive flux, gas mass flux and applied flux
  • Mechanical model, with appropriate temperature distribution, for thermomechanical analysis
  • Meshes used in axisymmetric thermal and axisymmetric/3D mechanical analysis that do not have to be identical and in which the temperature field can be interpolated between meshes

LMSSamcef Amaryllis Benefits

LMS Samcef Amaryllis helps you:

  • Calculate mass and volume loss
  • Measure the temperature (pressure and density) of a fixed point in a deforming mesh
  • Calculate the thermal balance on part of the structure
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