Thermal Analysis

What Is Thermal Analysis

Thermal analysis is an analytical technique whereby changes in the physical state of a substance or its products are evaluated as a function of temperature and time (in some cases). The type of physical change being studied determines the choice of analysis technique, one of which is computational fluid dynamics (CFD) thermal analysis. CFD thermal analysis couples the effects of heat transfer—i.e., conduction, convection, and radiation—with fluid physics to provide realistic solutions.

Thermal analysis can be steady-state or transient. The result from a steady-state thermal analysis is often used as a precursor for transient analysis, such as where the results from the former are used as initial conditions for the latter. Steady-state thermal analysis is used for determining temperatures, heat fluxes, and heat flow rates, while transient thermal analysis determines time-dependent thermal quantities.

Why Is Thermal Analysis Important?

Heat plays a significant role in the design of engineering systems such as electronic devices, aerodynamic components, and cooling systems. CFD thermal analysis simulations extract information to accurately predict temperature distribution, heat transfer rates, hot spots, airflow fields and patterns, and heat flux rates. Designers can then use this data to design a better thermal management solution and ensure their design will be safe to operate. In aerodynamic applications, thermal analysis is a must, especially at high speed, given the aerodynamic heating and pressure conditions.

How Does Thermal Analysis Work?

CFD thermal analysis builds a model of the system to be evaluated, enabling designers to review the thermal challenges in the design under various conditions. Moreover, the thermal review obtained from CFD thermal analysis is closer to the field results. Often the thermal analysis model considers the temperature dependency of the material, properties of fluids (air, water, or any other coolants), contact conditions, and other structural and environmental non-linearities.

With CFD thermal analysis, the thermal and flow attributes can be directly assigned to the design geometry for optimization. This allows designers to plug and play with different materials, energy, and turbulence models and to finalize the combination that offers maximum heat removal prior to development. The cost of thermal failures or design reworks based on prototype thermal testing is prohibitive, so utilizing comprehensive CFD thermal analysis in the early design stages will continue to be a best practice.

Thermal Analysis with Cadence

The Cadence portfolio of system analysis tools consists of Fidelity CFD Software and Celsius Thermal Solver, both of which allow users to perform thermal analysis simulations for their applications on-premises or using the Cadence OnCloud platform.

Fidelity CFD Software is an end-to-end solution for all CFD-related applications. The dedicated tools within the Fidelity CFD environment can solve each step of any thermal analysis simulation quickly and efficiently. Fidelity CFD can solve multidisciplinary modeling, analysis, and optimization for conjugate heat transfer (CHT) coupling flow, fluid-structure interactions (FSI), and fluid-chemistry and multiphase interactions such as combustion. Further, it has an intuitive and application-driven interface with the Python API and optimization module.

The Celsius Thermal Solver combines finite element analysis and computational fluid dynamics to enable system-level analysis. Using the Celsius Thermal Solver, engineering teams can design chips that are aware of the ambient condition. In addition, the tool performs both static (steady state) and dynamic (transient) electrothermal co-simulations based on the actual flow of electrical power in advanced 3D structures, providing visibility into real-world system behavior.