National Academies Press: OpenBook

Cost, Effectiveness, and Deployment of Fuel Economy Technologies for Light-Duty Vehicles (2015)

Chapter: Appendix D: Ideal Thermodynamic Cycles for Otto, Diesel, and Atkinson Engines

« Previous: Appendix C: Presentations and Committee Meetings
Suggested Citation:"Appendix D: Ideal Thermodynamic Cycles for Otto, Diesel, and Atkinson Engines." National Research Council. 2015. Cost, Effectiveness, and Deployment of Fuel Economy Technologies for Light-Duty Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/21744.
×

Appendix D

Ideal Thermodynamic Cycles for Otto, Diesel, and Atkinson Engines

End of compression pressures shown in Figure D.1 are reasonably representative of actual engines. However, combustion processes differ significantly in actual engines, compared to the idealized cycles. In the Otto and Atkinson cycle spark ignition engines, combustion does not occur at constant volume but instead extends over a significant number of crank angle degrees (as changes in cylinder volume occur). In diesel engines, combustion does not occur at constant pressure, but instead occurs with a shorter duration which results in an increase in pressure during combustion. For these reasons, in actual engines, the diesel engine will have higher peak cylinder pressures than spark ignition engines. This results in the need for a heavier engine structure to contain the higher peak cylinder pressures of diesel engines.

images

FIGURE D.1 Ideal thermodynamic cycles for Otto, Diesel, and Atkinson engines shown on pressure-volume (P-V) diagrams.
SOURCE: Paul Ronney (2013), University of Southern California, http://ronney.usc.edu.

REFERENCE

Ronney, P. 2013. Ideal Cycle Analysis. AME 436 Lecture 8, Spring. University of Southern California School of Engineering. http://ronney.usc.edu/AME436/Lecture8files/AME436-Lecture8.pptx. Accessed February 25, 2015.

Suggested Citation:"Appendix D: Ideal Thermodynamic Cycles for Otto, Diesel, and Atkinson Engines." National Research Council. 2015. Cost, Effectiveness, and Deployment of Fuel Economy Technologies for Light-Duty Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/21744.
×
Page 379
Next: Appendix E: SI Engine Definitions and Efficiency Fundamentals »
Cost, Effectiveness, and Deployment of Fuel Economy Technologies for Light-Duty Vehicles Get This Book
×
Buy Paperback | $124.00 Buy Ebook | $99.99
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

The light-duty vehicle fleet is expected to undergo substantial technological changes over the next several decades. New powertrain designs, alternative fuels, advanced materials and significant changes to the vehicle body are being driven by increasingly stringent fuel economy and greenhouse gas emission standards. By the end of the next decade, cars and light-duty trucks will be more fuel efficient, weigh less, emit less air pollutants, have more safety features, and will be more expensive to purchase relative to current vehicles. Though the gasoline-powered spark ignition engine will continue to be the dominant powertrain configuration even through 2030, such vehicles will be equipped with advanced technologies, materials, electronics and controls, and aerodynamics. And by 2030, the deployment of alternative methods to propel and fuel vehicles and alternative modes of transportation, including autonomous vehicles, will be well underway. What are these new technologies - how will they work, and will some technologies be more effective than others?

Written to inform The United States Department of Transportation's National Highway Traffic Safety Administration (NHTSA) and Environmental Protection Agency (EPA) Corporate Average Fuel Economy (CAFE) and greenhouse gas (GHG) emission standards, this new report from the National Research Council is a technical evaluation of costs, benefits, and implementation issues of fuel reduction technologies for next-generation light-duty vehicles. Cost, Effectiveness, and Deployment of Fuel Economy Technologies for Light-Duty Vehicles estimates the cost, potential efficiency improvements, and barriers to commercial deployment of technologies that might be employed from 2020 to 2030. This report describes these promising technologies and makes recommendations for their inclusion on the list of technologies applicable for the 2017-2025 CAFE standards.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    Switch between the Original Pages, where you can read the report as it appeared in print, and Text Pages for the web version, where you can highlight and search the text.

    « Back Next »
  6. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  7. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  8. ×

    View our suggested citation for this chapter.

    « Back Next »
  9. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!