|Title||K.D. Kim, W.H. Yoon, S.H. Ghal, H.I. Kim, C.S. Bae, “Optimization of Combustion System to Comply with IMO Tier 2 Regulation on HYUNDAI HiMSEN Engines”, CIMAC paper No. 201, CIMAC Congress 2010, Bergen, June 2010.|
K.D. Kim, W.H. Yoon, S.H. Ghal, H.I. Kim, C.S. Bae, “Optimization of Combustion System to Comply with IMO Tier 2 Regulation on HYUNDAI HiMSEN Engines”, CIMAC paper No. 201, CIMAC Congress 2010, Bergen, June 2010.
Combustion system is optimized through numerical simulation and experiment to com-ply with upcoming IMO Tier 2 regulation on HYUNDAI HiMSEN engines. Various studies have been made to validate spray and combustion models by comparing numerical results with experimental ones including spray tip penetration, cylinder pressure and NOx emissions. Performance and combustion simulation have been carried out to ﬁnd out the solutions for complying with IMO Tier 2 limit. Various intake valve closing times with higher compression ratio of turbocharger were evaluated by performance simulation to realize Miller cycle. Various fuel injection nozzle conﬁgurations and piston bowl shapes have been investigated to reduce NOx emissions by using combustion simulation.
Engine tests were performed to validate simulation results and to conﬁrm the IMO Tier 2 compliant engine, HYUNDAI HiMSEN models. Engine tests show that intensiﬁed early Miller cycle can improve SFOC and NOx at the same time. Intensiﬁed Miller cycle with reducing IVC up to 20deg. relative to IMO Tier 1 and higher compression ratio of turbocharger up to 5.2 reduces NOx by 8%. But extremely early or late Miller cycle deteriorates the engine starting and acceleration characteristics and has higher smoke at 10% load over invisible limit. The trade-off relation be-tween SFOC and NOx was generally measured in the variation of fuel injection nozzle conﬁguration and pis-ton bowl shapes. The optimum combination of Miller cycle, fuel injection nozzle conﬁgurations and piston bowl shape was selected for all HiMSEN engines with satisfying IMO Tier 2 limit. The engine test results with optimized internal measures show that NOx emissions were reduced below IMO Tier 2 NOx regulation without increasing fuel consumption of HYUNDAI HiMSEN engines.