Validated software tools for engine design
Vehicle exhaust is responsible for polluting the air in our cities and also contributes to climate change. European legislators have moved to severely limit the allowable exhaust pipe emissions. In the race to satisfy the new requirements, engineers are turning to computer-based methods to facilitate and accelerate the design process. Ford Werke AG combined its talents with those of other automobile manufacturers and research institutes in the MINNOX R&D project to reduce emissions of nitrogen oxides (NOx). They oversaw the collection of experimental data from a production test engine operated under different loads. Ford's engineers subsequently came up with a novel way to estimate the temperature of metal engine components by combining computational fluid dynamics (CFD) and finite element methods (FEM). FIRE, a CFD package developed by MINNOX coordinator AVL, was used to address heat transfer between the engine block, gas combustion and coolants. FEM software was used to provide information regarding additional thermodynamic parameters for the different material phases. Validation of model output showed that not only is accuracy improved, but the time required to perform simulations is also significantly less thanks to extensive automation of the procedure. This leads to better modelling of pollutant emissions since production of NOx depends strongly on engine temperature. The new tools will be exploited to optimise engine design to maximise NOx reduction.
