Fluid dynamic investigation of innovative intake strategies for multivalve internal combustion engines

The aim of the paper is to investigate the influence of novel opening strategies for intake valves on thepermeability and in-cylinder flow of a multivalve spark-ignition internal combustion engine. Specifically, thedeactivation of an intake valve and asymmetric valves lifts are analysed and compared to the standardsymmetric valves opening.To this purpose, a computational fluid dynamic (CFD) analysis is performed by using a finite volume code andan experimental activity is done at a steady flow rig.The investigation is carried out for different intake strategies and engine load conditions and the comparisonbetween CFD and experimental flow coefficients shows a good agreement.The results demonstrate that the proper combination of different valves strategies permits the effect of thethrottling process at medium and low engine load to be minimised, improving the breathability of the intakesystem, and creating more organised and energised mean flow structures within the combustion chamber.