intake flow interference analysis of combination intake port in diesel engine

In order to analyze the intake flow characteristics of a four-valve direct injection(di) diesel engine, the experiments and numerical simulations were conducted to investigate the flow coefficient, swirl ratio and intake flow interference of the following 4 combinations of intake ports: (1) helical (left) and tangential (right), abbreviation ; (2) tangential (left) and helical (right); (3) helical (left) and helical (right); and (4) tangential (left) and tangential (right).results show that the relative flow coefficient and swirl ratio could be directly reflect the interference of combined intake port, and when the ratio was close to 1, which showed that intake port had less interference ;and when the ratio was close to 0, which showed that the interference was serious. the relative flow coefficient of the 4 combinations of intake ports has little difference, but the relative swirl ration had significant difference in the whole valve lift range. and there had little interference between adjacent intake ports, but the swirl was strongly formed in cylinder at the maximum valve lift.