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. Since 1885, Dahlman has been providing industrial filtration solutions to clients  worldwide. All their products for the refining, oil & gas, petro chemical and  power generation industries are designed, developed, engineered and produced  in-house at Maassluis, near the busy port of Rotterdam.  For the power generation industries Dahlman also designs and produces  equipment for gasturbine (GT) packages, consisting of combustion air inlet and  exhaust systems (incl. silencers and filters), acoustical enclosures and  ventilation/anti-icing systems. The design of the ventilation system of a GT  enclosure is particularly complex, because many different require-ments have to  be fulfilled. In the first place the enclosure, which is barely larger than the  turbine itself, protects the surroundings from the enormous heat  and noise level emitted from the turbine. The  amount of thermal energy can exceed 1 MW for certain gas turbines.   However this insulation keeps the temperature in the enclosure high, which may lead to overheating and mal  functioning of the turbine and finally to a cost intensive shut down. Therefore the ventilation system of the GT  enclosure has to guarantee a sufficient cooling of the turbine. Furthermore the ventilation system is also used to  transfer potential explosive gases out of the enclosure. The presence of explosive gases (caused by for example  leakages in gas piping) is a seriously hazard  for fire/explosions which should be mini-  mized as much as possible,. It has to be  proven that the region, in which the local  gas concentration exceeds 50% of the lower  explosion limit (LEL), is only a small  fraction of the total air volume within the  enclosure. As the air flow requirements for cooling and  leak dispersion can be rather contradictive  Dahlman has asked FlowMotion to study the  air flow of a GT enclosure, which has currently been in the design phase. For this study the air flow through the  enclosure has been simulated with the help of CFD (Computational Fluid Dynamics).   In this simulation a virtual model of the turbine, the air ducts and the inner enclosure geometry have been developed.  The influence of the piping of the turbine on the flow along the turbine and thus on its heat transfer (including thermal  radiation) has been modelled by porous blocks. a reduction of the production costs.  Explosion in a Box Ventilation of a gas turbine enclosure Dahlman Filter Technology www.dahlman.nl streamlines gas bubble gas concentration