“Whoa! It’s like Spotify but for academic articles.”

Instant Access to Thousands of Journals for just $40/month

Improvement of Diesel Engine Performance by Variable Valve Train System

The effects of variable valve timing and lift are studied in order to improve the thermal efficiency of a diesel engine, while maintaining low emission levels. At high load conditions, early closing of one of the intake valves or early intake valve opening realizes an enhancement of swirl intensity without increased pumping losses, and retarded intake valve closing reduces the effective compression ratio, both of which result in an increased exhaust gas recirculation ratio and an advanced fuel injection timing. Consequently low NOx formation and an improved thermal efficiency can be achieved simultaneously. At low load conditions, the injected fuel is dispersed in the cylinder by air swirl because of the small fuel quantity, and the increased effective compression ratio achieved by the early intake valve closing becomes effective at reducing hydrocarbon emissions. It is confirmed that the variable valve timing and lift system introduced in this research can flexibly change the engine parameters that govern engine combustion at various engine operating conditions. As a result, a 40 per cent reduction of engine-out NOx emissions and 4 per cent improvement of fuel consumption in the New European Driving Cycle (NEDC) are achieved. Furthermore, low-end torque could be increased by 40 per cent, utilizing exhaust pressure pulsation by matching of exhaust valve opening timing, and the overlap of intake and exhaust valve opening around top dead centre in the intake stroke. To enhance these benefits a new piston chamber with deep valve pockets is developed and its effect is investigated. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png International Journal of Engine Research SAGE

Loading next page...

Sorry, we don’t have permission to share this article on DeepDyve,
but here are related articles that you can start reading right now:

Explore the DeepDyve Library

How DeepDyve Works

Spend time researching, not time worrying you’re buying articles that might not be useful.

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from Springer, Elsevier, Nature, IEEE, Wiley-Blackwell and more.

All the latest content is available, no embargo periods.

See the journals in your area

Simple and Affordable Pricing

14-day free trial. Cancel anytime, with a 30-day money-back guarantee.

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Best Deal — 25% off

Annual Plan

  • All the features of the Professional Plan, but for 25% off!
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.

billed annually