FKFS UserCylinder

The UserCylinder is a plug in for GT-Power and replaces the usual cylinder object there. During a GT-Power simulation, all the high-pressure parts of the cycle in the cylinder (compression stroke and power stroke) will, from then on, be calculated using FKFS in-house code.


Within an overall engine model, this enables more detailed and faster predictions about the processes in the combustion chamber. Important result parameters for the cylinder are, for example, combustion profile, fuel consumption, cylinder pressure profile, emissions as well as knocking and cycle fluctuations.

The application of UserCylinder is useful in different phases of engine development.


During the concept phase:

  • for comparing different turbocharging concepts with regard to fuel consumption and transient behavior,
  • for optimizing the compression ratio in the conflict between partial load and full load consumption (knocking),
  • for the variation of valve control times or valve lift profiles, by correctly illustrating the effects on combustion.


In the functional development, application and test phases of control units:

  • for estimating limits of running smoothness or knock limits,
  • for optimizing transient operating states on the gasoline or diesel engine,
  • by having the option of testing control unit functions on a virtual engine. 

In research projects and for teaching, the UserCylinder enables the construction of virtual test vehicles, which react qualitatively and quantitatively to changes in the boundary conditions in a sensible way. This can be used to gain greater understanding of the processes in the combustion chamber, and the overall interrelationships in the engine. This applies particularly when investigating the effects on combustion and emissions generation when the boundary conditions in the combustion chamber are changed.

© 2018 FKFS Forschungsinstitut für Kraftfahrwesen und Fahrzeugmotoren Stuttgart | Impressum | Datenschutz | AGB      
FKFS Facebook Page FKFS Xing Profile FKFS Linkedin Profile FKFS Youtube Channel