An Experimental Study of Swirl and EGR Effects on Diesel Combustion by Use of the Dumping Method

Experimental histories of major species total concentrations in the cylinder were obtained for a single cylinder TACOM-LABECO diesel engine by using a dumping technique to quench the cylinder gas rapidly at various selected crank angles during the combustion and expansion process.

Performance data using both an eight-hole and four-hole nozzle were taken for a range of swirl ratios, exhaust gas recirculation percentages and injection timings at medium load and 1000 RPM.

Seven dumping histories were obtained all at 1000 RPM and 0.5 equivalence ratio for selected combinations of two injection timings (15 and 25), two EGR values (0 and 10%), two swirl ratios (2.5 and 4), and two nozzle tips (4 and 8 hole). These histories show cylinder-averaged values of NO_x, CO and H₂ as a function of crankangle.