While this image might make you think that the whole front end of that car is being melted from intense heat, the intense heat part is at least right. It is actually a simulation of the key-off/heat soak situation that is arising more frequently, particularly in new cars because of the tighter under hood packaging that exists, as well as the close-coupled catalysts. This can lead to component degradation—or failure. So thermal engineers must determine the peak under hood temperatures during key-off/soak, and then take countermeasures to prevent thermal failure. That said, it is a difficult task to accomplish. For example, it has been determined that when cars are run in climatic wind tunnels and a thermocouple is used to check part temperatures, the readings can be as much as 10°C off. Consequently, there is a move toward simulating what’s occurring under the hood by a number of OEMs, including Jaguar Land Rover, with software developed by Exa (exa.com). The company’s PowerFLOW software combined with its PowerTHERM simulates both the heat conduction in solids as well as thermal radiation effects. Then the PowerVIZ visualization software permits thermal engineers to see how flow patterns evolve over time. All this without having to build physical properties.Â
