Modelling advanced engine combustion concepts / Driven by societal challenges on CO2 emissions and energy security, new pre-mixed combustion concepts, Reactivity Controlled Compression Ignition (RCCI) and Partially Premixed Combustion (PPC), are studied in CI engines. These concepts are ultra clean, reported to have very high indicated thermal efficiencies (57-59% in literature), and enable the usage of a wide range of (bio-) fuels (fuel flexibility). The combustion in such approaches is controlled by auto-ignition of a largely pre-mixed mixture of higher octane fuels, air and exhaust gas. Compared to classical diesel combustion, they lack direct control of combustion phasing and of rate of heat release and in general do not reach the same fuel conversion efficiency. Focus of the research is on maximizing efficiency and load range, specifying the best practical fuel (mix), and making the concepts robust for varying operating conditions. Given the sensitivity of these new concepts to operating conditions, advanced numerical combustion models will be developed based on single cylinder data and employed to optimize the fueling strategy and pin point the sources of the emissions and reduced fuel conversion efficiency. This is the main of topic of this PhD position. It is part of a larger project (4PhD positions) funded by the Dutch Science foundation NWO, DAF and TNO.
Challenge / Combustion in engines in general is controlled by chemical kinetics. Mechanism describing this accurately consist of many species and reactions which poses a big challenge for numeric simulation of engines. In this project an advanced and efficient approach, F(lamelet)G(enerated)M(anifolds)-method, is used to tackle this issue. The approach however is never used in a domain where both flame-propagation and auto-ignition may be relevant. This is a serious challenge to be investigated in this PhD project.
Project aim and description / The project aim is to develop the FGM method for the application in these RCCI and PPC engine concepts. The FGM method is already applied in turbine (pre-mixed flame propagation) and classical diesel engine (non-premixed, auto-igniting diesel spray flames). The model needs to be extended towards an accurate description of RCCI and PPC combustion which are dominated by auto-ignition of a stratified charge and/or flame-propagation. Hence the methodology needs to automatically account for the relevant mode occurring (auto-ignition vs flame propagation). This would a major breakthrough for the FGM method in combustion engines.
Working location / The position will be a so-called Dual PhD position between the TU/e, Power and Flow group (
www.tue.nl/power-flow ) at the Mechanical Engineering department of the Eindhoven University of Technology and the CMT institute (
https://www.cmt.upv.es/ ) at the Universitat Politècnica de València (UPV). The first two years the candidate will be stationed at the Eindhoven University of Technology working on developing the FGM method for RCCI and PPC combustion. The second two years will be spent at the Universitat Politècnica de València where the focus will shift towards the flame propagation part. However, if the progress is fast already in the first years this aspect can be studied.