Numerical Simulation Study on Swirl Chamber Diesel Engine with Dual Channel and Expansion Angle

The connecting channel of swirl chamber has significant impact on the performance of diesel engine. Based on diesel engine BH175F1, the thesis first proposes the idea of dual channel insert with expansion angle and then designs nine solutions which differ in the expansion angle between channel A and B by 5° interval. Furthermore, with the help of FLUENT software, the thesis works out the airflow pattern of the swirl chamber during injection. Results indicate that when expansion angle of channel A is constant, the vortex strength increases with the enlargement of the expansion angle of channel B, when expansion angle of channel B remains 10°, the swirl ratio respectively reaches 4.7, 3.9 and 4.2, all of which have exceeded the optimum swirl ratio range and that is bad for the performance. In turn, when B is fixed, the increase of expansion angle of channel A is favorable to the airflow in swirl chamber, swirl ratio stays at 3.2 if expansion angle of channel A is 10° and B 5°. In these cases, the performance of the swirl chamber diesel engine will be improved, and certain basis as well as technical reference can be cited for the improving the performance.