About Conjugate Heat Transfer

A conjugate heat transfer (CHT) simulation describes the heat transfer between solid structures and the fluids flowing over or inside them as a result of thermal interaction. The native CHT capability in Fluid Scenario Creation couples the heat transfer analysis in fluids and solids into a single native simulation process without using co-simulation.

In a native CHT simulation, the solid is treated as a rigid body, and you can perform a steady-state or transient analysis of the problem. By contrast, CHT co-simulations in the Multiscale Experiment Creation app are always transient analyses, and they enable you to use a full structural model and study the deformation effects on the solid. The computational cost of co-simulations is usually much higher as well. For more information about co-simulation, refer to the Multiscale Experiment Creation Guide.

One example of native CHT simulation is the heat transfer between an electronic chip on a printed circuit board and the ambient air. Power dissipation in the chip generates heat, and the heated surface of the chip induces a temperature-dependent density differential in the surrounding air, leading to a buoyancy-driven natural convection process external to the surface. Heat is transferred from the chip to the ambient air by convection.

Within a CHT simulation, the thermal analysis case uses a heat transfer step to calculate the heat transfer within the structure. The flow analysis case uses an incompressible flow step to solve the energy equation for the fluid flow surrounding the structure. The simulation enables you to identify the surface at the interface boundary between the fluid domain and the structure; for example, the top surface of a computer chip on a circuit board.

Native CHT simulations work well in both conformal and non-conformal interfaces; that is, the fluid mesh and solid mesh do not need to match each other. However, this type of simulation works best when these meshes have comparable mesh sizes.