PARALLEL ENGINEERING SIMULATIONS BASED ON FORMING SIMULATION OF A HEAT EXCHANGER PLATE

Normally, simulation regarding computational fluid dynamics (CDF), structural mechanics and heat transfer simulations in sheet metal applications are made without a forming simulated part. Instead the simulation is based on especially constructed parts, with some kind of nominal geometry, only for the specific simulation. This paper presents the use of sheet metal forming simulation of an advanced thin sheet metal part as input to other simulations. Here forming simulation provides input data for different parallel simulations: simulation of computational fluid dynamics (CFD), simulation of structural mechanics and thermal heat transfer simulations. From the forming simulation output e.g. pressed part geometry, it should be possible to use sheet metal thinning, residual stress and strain as input in other simulations later on. However, today it is not trivial to export and use the result from LS-DYNA to the desired application. We have developed a method for carrying a correct geometry into parallel simulations with input from forming simulated section. A special heat exchanger plate, with intensive and sharp patterns, was developed to study the influence of variations in geometry of the pressing tool. The sheet metal forming simulation was performed with LS-DYNA. A C++ program was developed to calculate new nodes in the surface of forming simulated section. This to be able to created a geometrically correct solid model as input in parallel simulations. A simulation of computational fluid dynamics was performed with forming simulated section of a heat exchanger plate as input to verify method. Result achieved from forming simulation regarding thickness variation and material inflow were compared with real pressing results for stainless steel material. The comparison showed good agreement between the simulations and the measured parameters on a processed heat exchange plate. Previously the design engineer could actually make real test tools and press metal sheets in the workshop. This is very expensive and even more important; it takes a lot of time. Here the forming simulation is a very powerful tool. Geometrically correct model achieved with described method and forming simulation is possible to use as input in simulation of computational fluid dynamics (CFD). In a similar manner the simulation of structural mechanics and thermal heat transfer are possible to perform with thickness variations instead of nominal geometry. The sheet metal simulation is nowadays used for a number of different purposes. The main purpose is to detect problems with the tools. The second aspect is to be able to make other useful simulations with the geometry of the simulated heat exchanger plate and it is necessary to be well established in this IT-area to be a competitive manufacturer of heat exchanger plates in future.