Full Content is available to subscribers

Subscribe/Learn More  >

CFD Analysis of the Scavenging Process in Marine Two-Stroke Diesel Engines

[+] Author Affiliations
Fredrik H. Andersen, Johan Hult, Karl-Johan Nogenmyr, Stefan Mayer

MAN Diesel & Turbo SE, Copenhagen, Denmark

Paper No. ICEF2014-5438, pp. V001T01A002; 13 pages
  • ASME 2014 Internal Combustion Engine Division Fall Technical Conference
  • Volume 1: Large Bore Engines; Fuels; Advanced Combustion; Emissions Control Systems
  • Columbus, Indiana, USA, October 19–22, 2014
  • Conference Sponsors: Internal Combustion Engine Division
  • ISBN: 978-0-7918-4616-2
  • Copyright © 2014 by ASME


The scavenging process is an integral part of any two-stroke internal combustion engine regardless of being spark ignited (SI) or compression ignited (CI). The scavenging process is responsible for replacing the burned gas from the combustion process from the previous working stroke with fresh air/charge before the subsequent compression stroke. This implies that the scavenging process is integral to engine performance as it influence the initial condition for the combustion process, thus affecting the fuel economy, power output and emission of hazardous gases.

Two-stroke diesel engines for marine propulsion normally operates by the uniflow scavenging method, where the scavenge air enters the cylinder via inlet ports located near the bottom dead center and exits through one or several exhaust valves located in the cylinder head. This arrangement concentrates the airflow in one direction through the cylinder thus giving the method its name. The inlet ports are angled with respect to the local radius which will introduce a tangential velocity component to the air flow. The air moves axially through the cylinder in a swirling motion that favors mixing of fuel and air as the injected fuel is transported with the swirling air in the combustion chamber during fuel injection.

A known characteristic of swirling flows is an adverse pressure gradient in the center of the rotating flow which might lead to a local deficit in axial velocity and the formation of central recirculation zones, known as vortex breakdown. Optimal scavenging is achieved when the gas exchange is done by displacement, the local deficit in axial velocity will increase the mixing of burned gas and scavenge air thus decreasing the amount of pure displacement.

Copyright © 2014 by ASME



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In