Adiabatic Heating
The Adiabatic Heating node adds the equations for adiabatic heating in layered shells caused by abrupt changes in temperature due to fast deformation.
The increase in temperature is then defined by solving the distributed equation
where ρ is the density, Cp is the heat capacity at constant pressure, T is the temperature field, βah is the coefficient of adiabatic heating, and Qh corresponds to the heat sources due to mechanical dissipative processes.
Adiabatic heating is only available with some COMSOL products (see https://www.comsol.com/products/specifications/).
If the Composite Materials Module is available, adiabatic heating can be applied to arbitrary layers. The material properties, orientations, and layer thicknesses are defined using Layered Material node. The offset, and local coordinate system, in which material orientations and results are interpreted, is defined by Layered Material Link or Layered Material Stack node.
Without the Composite Materials Module, only single layer shells and membranes can be modeled. This is still useful, for example for some multiphysics couplings. For single layer materials, an ordinary Material node can be used, as long you include a Shell property group in which, for example, the thickness is given.
For a general description about layered materials, see Layered Materials in the documentation for the Composite Materials Module.
Boundary Selection
It is only possible to select boundaries which are part of the selection of a layered material defined in Layered Material Link or Layered Material Stack node.
Shell Properties
Select the layers in which adiabatic heating is to be modeled.
Table 6-61: Layer Selection
When Use all layers is not selected.
If the same layer is selected in two nodes being active on the same boundary, the contributions will be exclusive
For a general description of this section, see Layer and Interface Selections in the documentation for the Composite Materials Module.
Initial Values
Enter the Initial temperature Tini. The default value is 293.15 K.
Thermodynamics
The density ρ is taken from the material model (Linear Elastic Material or Hyperelastic Material).
The default Heat capacity at constant pressure Cp uses values From material. For User defined, enter an expression or value. The default value for the User defined is J/(kg·K).
Enter the Coefficient of adiabatic heating, βah. The default value is 1 (dimensionless), which means that dissipative processes contribute 100% as heat sources.
Select the Dissipative heat sourceInclude all dissipative sources or User defined.
The Dissipative heat source list makes it possible to include specific heat sources for the adiabatic heating. Enter a value or expression for the heat source Qh to include. For instance, the dissipated energy density due to creep is available under the variable shell.Wc and due to viscoplasticity under the variable shell.Wvp. Here solid denotes the name of the physics interface node.
Time Stepping
The Backward Euler method is not available with the Layered Shell interface neither with the Layered Linear Elastic Material nor the Layered Hyperelastic Material in the Shell and Membrane interfaces.
Domain ODEs
No settings are needed for the Domain ODEs method. However, this method adds degrees-of-freedom that are solved as part of the general solver sequence. The scaling of this field can affect the convergence of the overall solution.
Location in User Interface
Context Menus
Ribbon
Physics tab with Layered Shell selected: