Effects of tangential air passages to piston bowl on the performance of a DI diesel engine

In this experimental study, the effects of providing tangential air passages to piston bowl for better fuel energy conversion in terms of engine performance were investigated using a DI (direct injection) diesel engine. For this purpose, the standard engine piston having Hemispherical Combustion Chamber (HCC) was modified into Toroidal Reentrant Combustion Chamber (TRCC) and then into Toroidal Reentrant Combustion Chamber with Tangential Air Passages (TRCC-TAP) that have the same volume as that of the baseline engine without modifying the compression ratio. From the experimental investigations, it was observed that piston having TRCC-TAP showed improvement in terms of BTE and BSFC by about 2.3% and 4.4%. Substantial improvements in reduction of emission levels particularly for CO, UBHC and smoke were also observed for TRCC-TAP by about 26.4%, 12.96% and 3.4% respectively compared to HCC. The combustion analysis too showed improved characteristics for TRCC-TAP compared to HCC at all loads of operation.