High Temperature Fans
European Thermodynamics were asked to look at an automotive headlamp application whereby the potential heat output from the LED's could reach 150 degreesC without any thermal management assistance. Similarly, within the same project, cold-start and frost conditions would make the LED's inefficient until a pre-warm up of the components had been instigated. The project brief was to ensure the LED circuit could operate effectively between -20 and +120degreesC.
Initially, we divided the problem into two parts and initially modelled the headlamp system using Ansys CFX and Solidworks CFD software in order to obtain a theoretically known thermal performance prior to developing thermal management modules.
For the cooling side, we engaged with a prime cooling fan manufacturing partner and jointly developed a 40mm x 40mm x 28mm deep fan model that contained a modified ball bearing system that could operate continuously within an ambient temperature of +120 degreesC. The bill of materials (BOM) contained various ‘uprated’ components and circuitry to endure the environment and the new model was then subjected to environmental chamber tests by the customer in order to verify the critical expected lifetime required.
Acoustic noise was also an initial consideration. Our thermal modelling engineers designed a high performing material (A356: 160w/m.k) die-cast heatsink assembly which includes the useof T-Global’s new range of silicone-free thermal putties between device and heatsink. This not only assisted the required cooling performance but also was designed in order to maintain ‘in system’ minimum acoustic noise output, which helped to reduce overall broadband noise and shifted any pure tone frequencies to within an acceptable level.
With respect to the pre-warm up of the LED's, we are currently in the process of obtaining patents and IP acknowledgements for the method and technology used. This will result in a new product for automotive engineers to gain access to in order to solve their potential ‘cold start’ issue.
The new fans are available to order now (minimum order quantities apply).