Consumption map
Aconsumption maporefficiency map[1]is achartthat displays thebrake-specific fuel consumptionof aninternal combustion engineat a givenrotational speedandmean effective pressure,ingramsperkilowatt-hour(g/kWh).
The map contains each possible condition combining rotational speed and mean effective pressure. Thecontour linesshow brake-specific fuel consumption, indicating the areas of the speed/load regime where an engine is more or less efficient.
A typical rotation power output,P(linear to), is reached on multiple locations on the map that differ in the amount of fuel consumption.Automatic transmissionsare therefore designed to keep the engine at the speed with the lowest possible fuel consumption for a given power output under standard driving conditions.
Overallthermal efficiencycan depend on the fuel used;dieselandgasolineengines can reach up to 210 g/kWh and about 40% efficiency.Natural gascan yield an overall efficiency of about 200 g/kWh.[2]Average fuel consumption values are 160–180 g/kWh for slowertwo-strokedieselcargo shipengines usingfuel oil,reaching up to 55% efficiency at 300 rpm; 195–210 g/kWh forturbodieselpassenger cars; 195–225 g/kWh for trucks; and 250–350 g/kWh fornaturally aspiratedOtto cyclegasolinepassenger cars.[3]
Literature
[edit]- (German) Richard van Basshuysen:Handbuch Verbrennungsmotor,Fred Schäfer; 3. Auflage; 2005; Vieweg Verlag
References
[edit]- ^Dieter Lohse und Werner Schnabel:Grundlagen der Straßenverkehrstechnik und der Verkehrsplanung: Band 1,Beuth Verlag, 2011,ISBN9783410172710.
- ^Rainer Golloch,Downsizing bei Dieselmotoren,Abschnitt2.1.3 Verbrennung,1.
- ^Table 1 in Konrad Reif, "Dieselmotor-Management im Überblick",Abschnitt Springer Fachmedien Wiesbaden 2014,ISBN978-3-658-06554-6