Georges El Hajj's PhD Defense in January 2022

Georges El Hajj completed his PhD within the framework of the partnership entitled "Experimental characterisation and phenomenological modelling of knock occurence in turbocharged SI engines". Knocking is one of the main technical barriers to improving engine efficiency and therefore the entire powertrain. In this thesis, Georges El Hajj characterised the occurrence of knocking on a three-cylinder supercharged direct injection internal combustion engine installed on the LHEEA test bench. The impact of engine control parameters was characterised (such as injection laws, valve timing, intake air temperature, coolant temperature and lubricating oil temperature). This testing was then used as the basis for developing a new knock model calibration method. Once calibrated, the knocking model was integrated into a full engine simulator (GT Power environment).

Georges El Hajj defended his PhD on 13 January 2022 before panel comprising:
 

• Prof. Jérome BELLETTRE, Université de Nantes
• Alan KEROMNES, Université de Limoges
• Prof. Christine ROUSSELLE, Université d'Orléans
• Alessio DULBECCO, Research Engineer, IFP Energies Nouvelles
• Olivier DAVODET, Numerical modelling expert, Stellantis -CEMR
• Prof. Alain MAIBOOM, Centrale Nantes
• Prof. Xavier TAUZIA, Centrale Nantes

 

Testing and deployment of calibration methods developed within the framework of the Stellantis partnership

Work carried out since the beginning of the partnership focused on developing models and calibration methods for the pre-calibration and calibration of automotive powertrains. The aim is to optimise the architectures and their development while drastically reducing the need for physical testing on test benches. The models developed within the framework of the partnership are currently being tested on a new platform while being deployed internally at Stellantis.
   

Experimental study and modelling of heat transfers under the bonnet

A new research area within the partnership relates to the experimental study and modelling of heat transfers under the vehicle's bonnet. A powertrain simulator was developed from the outset of the partnership. The boundary conditions were defined (ambient temperature and pressure, ambient convection level, etc.). It is now a question of changing scale by modelling the powertrain as well as its immediate environment (convection under the bonnet at various points, air flow and heat flow at the heat exchangers, local temperatures and air speeds, etc.). To this end, a series of experiments are underway on the laboratory's vehicle test bench in order to characterise all of the physical phenomena for different vehicle operating conditions. The first building blocks of the complete model are being developed concurrently.
 
> Learn more about the programme