Transient Numerical Computation of the Temperature of Electronic Devices in Passenger Cars: Flow Simulation in Electronics Cavities Available to Purchase

To compute the temperature of an electronic system submitted to time-dependent thermal loads, the problem of multi-scale coupled heat transfer modes is solved by means of co-simulation strategies. These coupling strategies use adapted codes for the prediction of each transfer mode, e.g. a CFD code for the computation of convection and a FE code for conduction. In this paper, numerical models to solve the flow in typical electronic enclosures are investigated, in particular regarding mesh requirements and turbulence modeling. First, the accuracy of a steady-state approach for the computation of natural convection in a cavity heated from below is examined for a large range of Rayleigh number covering time-dependent convection. Then, a steady-state method for fan flow simulation is presented and validated in comparison with the fan performance curve measured in a test-rig. Finally, different numerical models for flow computation through thin grills of an electronic system are discussed regarding the fan mass flow rate and the establishing pressure distribution.