Anwendungsbeispiele: Strömungsmechanik

Heat Transfer

Thermal Analysis Using FLUID116 Elements in ANSYS

Task

The aim of this analysis is to estimate the stationary temperature distribution in an IGBT module. The module is attached to a heat sink, which has one cooling channel. A power loss occurs in 2 chips at the top of the module.

Solution

For the described task, a thermal Finite Element Model was set up in ANSYS.
The module and the heat sink were meshed with volume elements. The cooling channel was meshed with FLUID116 elements.
FLUID116 is a line element with pressure and temperature degrees of freedom, which can transport heat and mass in a channel system. In the present case only the temperature degree of freedom was adapted. (Keyopt(1)=1).
The inside of the channel was meshed with SURF152 elements and convection was accounted for by setting the Keyopt(2)=2. The temperature and flow dependant heat transfer coefficients were evaluated through Nusselt numbers.
The flow rate in the channel was given and the inlet flow temperature was prescribed to 20°C. At all other boundaries natural convection with a film coefficient of 5 W/(m²K) to surrounding air 20°C was assumed.

Benefits with FLUID116

The use of FLUID116 elements in ANSYS offers a wide range of possibilities within thermal analyses involving channel systems and presents an accurate and “easy to use” alternative to more costly and complex CFD-approaches.

Consulting_Flyer_CADFEM_Thermalanalyse_IGBT_Module.pdf [1.1MB]