Use this node with 2D components to model domains with another thickness than the overall thickness that is specified in the Heat Transfer interface Physical Model section. In 2D geometries, the temperature is assumed to be constant in the out-of-plane direction (z direction with default spatial coordinate names). The heat equation is modified to account for that. See Equation 4-119 and Equation 4-120.

Specify a value for the Thickness dzof the domain in the out-of-plane direction. This value replaces the overall thickness in the domains that are selected in the Domain Selection section, and is used to multiply some terms into the heat equation.

Physics Tab with interface as Heat Transfer, Heat Transfer in Solids, Heat Transfer in Fluids, Heat Transfer in Porous Media, Heat Transfer in Building Materials, Bioheat Transfer, Heat Transfer with Surface-to-Surface Radiation or Heat Transfer with Radiation in Participating Media selected:
Domains>interface>Change Thickness