A METHOD FOR DETERMINING THE RPM REPRESSION OF SUPERCHARGED HIGH-POWER MARINE DIESEL ENGINES

The highly-supercharged medium-speed four-stroke Diesel propulsion engine, particularly if it drives a fixed-pitch propeller, may under certain operating conditions be subjected to "rpm repression". This can occur if (because of increased hull-resistance, for example) the engine is already operating under comparatively high load when still more power is required; if the engine cannot develop this extra power despite an increase in mep, its speed will fall in accordance with the power-characteristic curve until a new equilibrium is reached. Under very unfavourable conditions, this rpm drop may be as much as 30% or more, and can result in excessive thermal loading of the engine and other difficulties. The Author discusses these phenomena in relation to the engine/turbocharger system, and presents a mathematical simulation developed to provide a means of predicting the permissible speed-reduction during repression, taking the turbocharger design into consideration. This simulation is described in some detail, results obtained with it are compared with experimental results, and the effects of parametric variations are discussed. The article is based on investigations carried out at the University of Hanover. Order from BSRA as No. 49,958.

  • Availability:
  • Corporate Authors:

    Franckhlsche Verlagshandlung

    Pfizerstrasse 5, Postfach 640
    7000 Stuttgart 1,   Germany 
  • Authors:
    • Grohn, M
  • Publication Date: 1978-9

Language

  • German

Media Info

  • Features: References;
  • Pagination: p. 377
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00194248
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Jun 13 1979 12:00AM