Diesel engines are, and will continue to be, significant contributors in powering both motive and stationary needs for many years to come. Engines design and performance continues to develop to meet both fuel efficiency and emissions control requirements. Turbochargers, a key component in modern diesel engine, have been significantly improved over several decades, allowing production of higher power outputs, lower emissions levels, increased durability and improved efficiency.
Diesel engines are inherently more efficient than gasoline engines. Typically, a diesel powered vehicle can be driven further on a gallon of fuel. Some studies have shown an increased efficiency of up to 35% over a gasoline engine.
Added to this are the advances over the last 40 to 50 years in reducing pollution from diesel engine exhaust. Improvements in engine design, cleaner diesel fuel produced by sulfur content reduction, and additional emission controls technology have all contributed to significant reductions in emissions.
With advances in forging technology, turbocharger components are now being produced from forgings with significant durability and performance advantages over both casting and machined components used in years past.
Alloys and processes developed for the aerospace industry are being cost effectively used in production of turbochargers. Experiments with new, lighter weight alloys that can survive the high speed and temperatures required to take the next step in improving performance are being conducted. These experiments may lead back to improvements in aerospace components, where durability and light weight are critical requirements.
Forgings made from mechanically alloyed powders, one of the process techniques used in aircraft engine production, may soon provide cost and performance criteria for a variety of diesel engine components. The components may be lighter, stronger and more durable allowing further improvement in engine power to weight ratio.
A process innovation Queen City Forging implemented with the Oak Ridge National Laboratory was the use of rapid heating technology for turbocharger aluminum impellers for diesel engines. Average heating time compared to traditional methods was reduced from as much as two hours to 15-20 minutes in an infrared oven. This modification quadrupled productivity while consuming one-third less energy. The technology also resulted in improvements in component strength and fatigue life.
The bottom line is that diesel engines are not going away. New technologies allow diesel engines produced today to maintain a critical role in powering our nation.