Modelling of a Variable Venturi in a Heavy Duty Diesel Engine
Independent thesis Basic level (professional degree)Student thesisAlternative title
Modellering av variabel venturi i en dieselmotor för tung lastbil (Swedish)
The objectives in this thesis are to present a model of a variable venturi in an exhaust gas recirculation (EGR) system located in a heavy duty diesel engine. A new legislation called EURO~4 will come into force in 2005 which affects truck development and it will require an On-Board Diagnostic system in the truck. If model based diagnostic systems are to be used, one of the advantages is that the system performance will increase if a model of a variable venturi is used.
Three models with different complexity are compared in ten different experiments. The experiments are performed in a steady flow rig at different percentage of EGR gases and venturi areas. The model predicts the mass flow through the venturi. The results show that the first model with fewer simplifications performs better and has fewer errors than the other two models. The simplifications that differ between the models are initial velocity before the venturi and the assumption of incompressible flow.
The model that shows the best result is not proposed by known literature in this area of knowledge and technology. This thesis shows that further studies and work on this model, the model with fewer simplifications, can be advantageous.
Place, publisher, year, edition, pages
Institutionen för systemteknik , 2002. , 59 p.
Technology, Exhaust gas recirculation, On-board Diagnostic, Flow meter, Model Based Diagnostic, Restriction, Compressible, Incompressible
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-1531OAI: oai:DiVA.org:liu-1531DiVA: diva2:18855