A simulation study into the Atkinson cycle engine utilizing adjustable crank mechanism

Technologies that improve the efficiency of internal combustion engines are attracting ever-growing interest due to increasing demands concerning fuel economy and exhaust emissions. For years, engine evolution was focused on software or control devices development, with acceptance of only small mechanical changes to the well-established engine design. Recently, researchers and engineers put their attention to large mechanical changes to allow achieving high fuel efficiency. In the current study, a set of simulation experiments was performed to investigate the potential of Atkinson cycle realization using a modified Atkinson crank mechanism. The latter was modified by using excenter pin which additionally enabled control of compression ratio as well as the ratio between compression and expansion. Investigated solution was analysed under spark ignition operation and compared to the standard crank mechanism. The simulations were performed using AVL BOOST software. The model was validated using standard spark ignition engine measurement data. Afterwards, the engine was modified to investigate above mentioned strategies to improve thermal efficiency. The research successfully identified strategies, which allow control of engine aspiration and combustion, to hasten real-world application of these advanced combustion systems.