Browse Publications Technical Papers 2019-01-0231

An Exploratory Look at an Aggressive Miller Cycle for High BMEP Heavy-Duty Diesel Engines 2019-01-0231

Through aggressive application of the Miller Cycle, using two-stage turbocharging, medium speed diesel marine and stationary power engines are demonstrating over 30 bar rated power BMEP, and over 50 percent brake thermal efficiency. The objective of this work was to use engine cycle simulation to assess the degree to which the aggressive application of the Miller Cycle could be scaled to displacements and speeds more typical of medium and heavy truck engines. A 9.2 liter six-cylinder diesel engine was modeled. Without increasing the peak cylinder pressure, improved efficiency and increased BMEP was demonstrated. The level of improvement was highly dependent on turbocharger efficiency - perhaps the most difficult parameter to scale from the larger engines. At 1600 rpm, and a combined turbocharger efficiency of 61 percent, the baseline BMEP of 24 bar was increased to over 26 bar, with a two percent fuel consumption improvement. As turbocharger combined efficiency increased, to over 75 percent as seen in large, medium speed engines, over 29 bar BMEP was achieved, with over six percent fuel consumption improvement. Similar results were seen at 1200 rpm, with a maximum BMEP of over 34 bar, and greater than two percent fuel consumption improvement, at a turbocharger combined efficiency of 61 percent. Application considerations including speed and load range, and emission constraints are discussed.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:

Impinged Diesel Spray Combustion Evaluation for Indirect Air-Fuel Mixing Processes and Its Comparison with Non-Vaporing Impinging Spray Under Diesel Engine Conditions


View Details


Detection of Cylinder-to-Cylinder Injection Variation in a Four-Stroke Diesel Engine by Monitoring the Turbocharger Speed


View Details


Effect of Variable Geometry Turbocharger on HSDI Diesel Engine


View Details