Tool options in Celsius Thermal Solver

When you launch the Cadence Celsius Thermal Solver by using Programs > Cadence Sigrity 2022.1 > Celsius Thermal Solver, you get four tool options, of which three can be invoked, as shown below:

You may have some confusion as to which tool option you should launch. It is important to know which of these options should be used in your application.

Solid Objects Simulation for 3D Structures

This uses the 3D Finite Element Analysis (FEA) approach to solve conduction of geometry in 3D structures. This option does not perform a CFD or actual flow simulation, but it lets you define a boundary condition. The boundary condition is effective heat transfer coefficients (convection and/or radiation) attached to a fixed ambient temperature. This simulation is ideal for detailed conduction simulation with complex geometries, where convection and radiation effects are simplified with a boundary condition.

Solid Objects Simulation for Layered Structures

This includes the 2.5D layered structures and FEA approach to solve conduction. This is equivalent to many of the Sigrity toolsets. This FEA engine utilizes effective heat transfer coefficients (convection and/or radiation simplified effects) as a boundary condition like the Celsius 3D FEA solver. However, the effective HTCs are automatically applied based on the flow velocity as a user’s input. It extracts effective HTC values based on empirical correlations of the flow over a flat plate. Also, it has the heat transfer coefficient map import capability from the actual flow simulation solver in CFD to combine the best-of-both worlds approaches (solids for FEA and fluids for CFD).

Fluid Flow Simulation

This 3D Computational Fluid Dynamics (CFD) tool utilizes a Finite Volume Analysis (FVA) to solve both solids (conduction) and fluids (convection/radiation). However, the conduction part is simplified with rectangular blocks or cuboids, whereas the fluid domain is done by the actual flow simulation to capture the convective and radiation effects in a detailed manner. Also, it has an import capability of the simplified CFD model from the 2.5D layered structure FEA solver. It can open the 3D FEA database directly as well.

Thermal Network Simulation

This is an unreleased function of the toolset.

Team SimTech 

Cadence Design Systems