Offices: The Netherlands Leeghwaterstraat 21 2628 CA Delft Tel.: +31 15 278 2907 Germany Weenermoorer Str. 193 26826 Weener Tel.: +49 4953 922 969 Consultancy for Heat Transfer and Fluid Dynamics CFD makes fluid dynamics visible. We solve every Flow problem. Nedap develops and manufactures innovative electronical  systems for measurement, controlling and automization  purposes. In nearly all products a huge amount of  electronical components are packed in very limited space. A  part of the components releases quite some heat to the air  in the housing. Since the competitive market asks for even  smaller apparatus with increasing power, optimising the  heat transfer is an ongoing process for Nedap.  Therefore FlowMotion was asked to optimise a finned  passive cooler with respect to heat transfer and size. To get  the most data about the velocity and the temperature  distribution of the cooling air passing the cooler, CFD  (computational  fluid dynamics)  calculation has  been chosen as  the primary  investigation method, to simulate the flow and the heat transfer.  For the flow simulation a 3D model of the real finned cooler and the  surrounding space have been developed. Afterwards the so-called calculation grid has been built up. This has to be  done with great care, since the calculation grid has a dominant influence  on the accuracy of the simulation. In the performed simulations not only  the heat transfer the the flow, but also thermal conductivity and thermal  radiation has been taken into account.  For the development of electronical cooling CFD offers following  advantages compared to building prototypes in combination with  measurements. CFD calculations are less time and cost consuming and the  depth and the quality of the obtained data is much higher. Therefore  various geometries of the cooler has been investigated in detail. The  analysis of the simulation results led to a deeper insight in the physics of  the heat transfer of a finned cooler and the benefit of certain geometrical  changes could be shown before a real prototype has been built.  Cooling of electronics in limited space Optimisation of cooling fins for a power supply Nedap www.nedap-energysystems.com Pathlines Temperature