Two diesel engines representative of the four-stroke cycle and two-stroke cycle main propulsion units installed in U.S. Coast Guard WPB class cutters were operated in a test environment in an attempt to demonstrate significant fuel savings associated with water-in-fuel emulsions. The engines were connected to a dynamometer in a laboratory test cell. A prototype fuel system was assembled that would supply unstabilized emulsions for which the water concentration could range form zero to 25 percent of the total volume of liquid supplied to the engine as fuel. An analysis of boat operation was performed in order to identify the most frequently used engine settings, and both engines were operated at test points representative of boat prop load performance. The test results for the four-stroke cycle engine indicated that an average diesel fuel saving of about 2.5 percent could be obtained at the most frequently encountered operating conditions using water concentrations of 15-25 percent. Statistical analysis procedures suggest a 90 percent confidence in the measured results. Significant reductions in exhaust smoke were also observed, although the exhaust stream opacity was low throughout the tests. For the two-stroke cycle engine, no statistically significant reduction in fuel consumption could be identified.

  • Corporate Authors:

    Southwest Research Institute

    6220 Culebra Road, P.O. Drawer 28510
    San Antonio, TX  United States  78228-0510

    Transportation Systems Center

    55 Broadway, Kendall Square
    Cambridge, MA  United States  02142

    United States Coast Guard

    2100 Second Street, SW
    Washington, DC  United States  20593
  • Authors:
    • Coon, CWJ
  • Publication Date: 1981-6

Media Info

  • Pagination: 155 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00346005
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: TSC-USCG-80-7
  • Contract Numbers: DOT-TSC-1587
  • Files: NTIS
  • Created Date: Jan 29 2003 12:00AM