Analysis of a tumbling motion using a clustering algorithm on dual-piv measurements: application to the in-cylinder flow of a miller cycle engine

This paper aims to study the internal aerodynamics of a Miller cycle gasoline engine. uses an over-expanded stroke recover more work, for same amount fuel, than classical Otto cycle. To achieve this, effective compression is made smaller expansion one by closing intake valves prematurely. The in-cylinder tumble flow then stops being driven valve jet before piston reaches bottom dead center, which disturbs movement. observed here on motored single-cylinder transparent engine coupled dual-PIV system. system allows two velocity fields per be measured. temporal evolution structures could thus followed, while keeping high number instantaneous measured traditional PIV systems. data are well adapted statistical analysis. A clustering analysis method, using k-means algorithm and data, described here. first part presents method defining criterion center rotation motion that can improve rates 17%. second classifies into three groups strong, medium weak intensity. characteristic quantities each group shows movements with rates, created upstream phase, give turbulence close top piston.