Development of an 1D simulation model to optimize performance and emissions of large gas engines

  • 1 LEC GmbH (Large Engines Competence Center), Graz, Austria
  • 2 LEC GmbH (Large Engines Competence Center), Graz, Austria; Graz University of Technology, Graz, Austria


The main subject of this paper is the development of a multicylinder engine model for the prediction and optimization of engine performance based on one-dimensional (1D) simulation. 1D simulation is widely used to preoptimize engine geometry and operating parameters to achieve performance targets and comply with operational and emission constraints. Due to the short calculation times, 1D simulation allows the evaluation of a larger number of variants. As new engine concepts are developed, many operating parameters are first defined and optimized with a 1D multicylinder engine model. This model illustrates the full complexity of the engine with its geometry, turbocharging and combustion parameters. In this paper the design of experiments (DoE) method is used in connection with 1D simulation to determine the optimal engine configuration as well as parameters related to the combustion process, i.e., valve timing, compression ratio, ignition timing, excess air ratio. This approach enables the determination of the maximum engine efficiency while taking the boundary conditions and the constraints of nitrogen oxide emissions (NOx) and knock into account. The method also enables the reduction of the cylinder-to-cylinder deviations by improving the gas dynamics and the fuel metering in the main combustion chamber and in the prechamber, which is especially important for the multicylinder engine. The simulation results are validated with experimental investigations on a single cylinder research engine.



  1. German Federal Government, 44. BImSchV - Vierundvierzigste Verordnung zur Durchführung des Bundes Immissionsschutzgesetzes* (Verordnung über mittelgroße Feuerungs- Gasturbinen- und Verbrennungsmotoranlagen - 44. BImSchV), 2019. https://www.gesetze-iminternet. de/bimschv_44/BJNR080410019.html (accessed June 16, 2021)
  2. Gothenburg Protocol “Protocol to the 1979 convention on long-range transboundary air pollution to abate acidification, eutrophication and ground-level ozone”. Gothenburg 1999, online:
  3. European Parliament and Council “Directive 2010/75/EU of the European Parliament and of the Council of 24 November 2010 on industrial emissions”. In: Official Journal of the European Union, vol. 53, 2010, No. L33
  4. Sauperl, I., Wimmer, A., Dimitrov, D., Zelenka, J., Pirker, G., Schneßl, E., Winter, H. : Ldm compact - a methodology for development of gas engines for use with low environmental impact non-natural gas, Strojniški Vestnik - Journal of Mechanical Engineering. 64, 12, p. 743-752, 2018
  5. Wohlthan, M., Pirker, G., Krenn, M., Wimmer, A.: LEC-MCheck – Eine Methodik zur Fehlerd iagnose an Motorprüfständen. 15th Conference „The Working Process of the Internal Combustion Engine“, 2015
  6. Pattas, K.; Häfner, G.: Stickoxidbildung bei der ottomotorischen Verbrennung, Motortechnische Zeitschrift, MTZ 34 (1973), 12
  7. Dimitrov, D., Chmela, F., Wimmer, A. (2005). Eine Methode zur Vorausberechnung des Klopfverhaltens von Gas-motoren. 4. Dessauer Gasmotoren Konferenz. (in German)
  8. Merker, G. P., Schwarz, Ch. (Hrsg.): "Grundlagen Verbrennungsmotoren", 2009, pp. 353-354.
  9. Krenn, M., Pirker, G., Mühlberger, M., Wimmer, A.: Einsatz der DoE-Methode zur simulationsbasierten Optimierung von Großgasmotoren. 14. Tagung Der Arbeitsprozess des Verbrennungsmotors, Graz, 2013.

Article full text

Download PDF