Corine Lacour

CORIA, French National Centre for Scientific Research

In the race for decarbonization of the power sector, H2 is found to be a better candidate as it can be readily produced in large scales from renewables (e.g. wind and solar energy). Nevertheless, the difference in the thermophysical properties of H2 in comparison to the conventional fuels possesses additional operational challenges. For instance, a...

La biomasse est une source d’énergie potentielle permettant de limiter la dépendance aux carburants fossiles et donc réduire l’empreinte carbone des machines thermiques. La combustion de pellets est une voie de valorisation de la biomasse efficace, mais elle nécessite encore des connaissances fondamentales. La composition chimique de la biomasse en...

The present work investigates the effect of jet-exit Reynolds number (Re) on soot particle size and flame temperature in n-butane jet flames. Correlation of temperature with soot volume fraction (fv), soot precursor (polycyclic aromatic hydrocarbons or PAH), and reaction zone (OH) is also examined. The investigated flames (Re=5000–21,500) are ident...

An automated spectral fitting algorithm (named Thermo NO-LIF) designed for the extraction of temperature information from experimental NO-LIF spectra is presented and analysed. With the aid of the Thermo NO-LIF, the high-accuracy (0.5%) of multi-line NO-LIF thermometry are demonstrated in the burnt-gases region of a near-adiabatic Bunsen-type premi...

Biomass valorization for energy production is considered as one of the best ways to overcome the petroleum’s depletion, move forward in the environmental protection concerns, but also to provide the energetic request. The combustion of biomass is an efficient valorization pathway but it still requires fundamental knowledge. To go deeper, some autho...

Tomographic PIV measurements require calibration accuracies of a fraction of a voxel throughout the entire investigation volume in order to provide reliable 3D data. This can be achieved today in a variety of applications by combining multiple planar recordings of a calibration target across the volume with the established self-calibration techniqu...

The three-dimensional measurement approaches are used more and more frequently in fluid mechanics, whether to measure flow velocity, to detect of surface location (vibration, liquid gas interface) or to obtain a scalar field (flame emission, LIF 3D, density. . . ). In practice, they consist mainly in observing the area of interest from different an...

The cycle to cycle combustion variability which is observed in spark-ignition engines is often caused by fluctuations of the early flame development. LES can be exploited for a better understanding and mastering of their origins. For that purpose appropriate models taking into account energy deposition, mixture ignition and transition to propagatio...

In order to guarantee good re-ignition capacities in case of engine failure during flight, it is of prime interest for engine manufacturers to understand the physics of ignition from the spark discharge to the full burner lightning. During the ignition process, a spark plug delivers a very short and powerful electrical discharge to the mixture. A p...

The purpose of the present work is to develop and to demonstrate the ability of the two-phase PIV by fluorescence technique for the study of two-phase flows dynamics. In particular, the dynamic of a high-pressure spray and its interaction with surrounding air is investigated in this study. For the single-phase flows, the PIV is a well-established t...

For over a decade, Tomographic PIV has been rapidly developing and is now applied in a wide range of domains in fluid mechanics [1]. This progress has been very rapid, especially thanks to the knowledge acquired during the last twenty years in the development of the PIV technique. This 3D optical measurement technique appears to be of high interest...

Engine internal aerodynamic reveals complex flow involving multi-scale turbulence, flow structure compression, two-phase interactions and are responsible for the mixing process and the engine performance and efficiency. Recent efforts have been made to describe in details in-cylinder flows either with temporal (HR-PIV) or spatial (Tomo-PIV) resolut...

This study is focused on the streamer-to-spark transition generated by an overvoltage nanosecond pulsed discharge under atmospheric pressure air in order to provide a quantitative insight into plasma-assisted ignition. The discharge is generated in atmospheric pressure air by the application of a positive high voltage pulse of 35 kV to pin-to-pin e...

L’utilisation de plus en plus fréquente des systèmes d’acquisition haute cadence pour la vélocimétrie par images de particules (PIV) permet l’application d’algorithme de traitement multi-images. Ces méthodes récentes ouvrent de nouveaux potentiels par rapport aux approches plus classiques basées uniquement sur un couple d’image de particules. Dans...

This work investigates the performance of the time-resolved PIV technique FTEE with an optimized 2-Frame PIV algorithm on both synthetic and experimental homogeneous isotropic turbulence (HIT). In the case of the synthetic tests, the algorithms are compared with a model that appropriately filters the full resolution HIT to replicate a perfect PIV t...

The present work focuses on the interaction between an electric discharge generated by a commercial pencil coil and surrounding air flow in terms of aerodynamics and heat release using advanced optical diagnostics. This investigation is firstly performed with pin-to-pin electrodes in air at rest under atmospheric pressure condition. The velocity of...

In an effort to reduce pollutant emissions and increase energy efficiency, partially premixed combustion has been integrated into many new combustion technologies. The present study investigated lean back-supported flames in a stratified combustion regime. This strategy leads to hybrid combustion regimes, ranging between fully premixed and fully no...

Oxycombustion diluted by recirculating flue gases is one of the most advanced innovating combustion technique to adapt carbon capture and storage (CCS) to industrial combustion plants. The dilution by flue gases with a large amount of CO2 impacts the flame behavior in terms of combustion efficiency, pollutant emission, radiative transfer and flame...

This paper presents a comparison between experiments and Large Eddy Simulation (LES) of a spark ignition engine on two operating points : a stable one characterized by low cycle-to-cycle variations (CCV) and an unstable one with high CCV. In order to match the experimental cycle sample, 75 full cycles (with combustion) are computed by LES. LES resu...

Multi-cycle Large-Eddy Simulation (LES) of flow and combustion in a single cylinder engine set-up are presented in order to validate the ability of this technique to reproduce cyclic combustion variability in a spark ignition engine. The simulated engine operating point is part of a larger experimental database acquired at IFP and specifically desi...

The objective of the present work is to provide, through the association of optical diagnostics on a well-chosen experimental configuration, new insights into the coupling of a vortical gaseous flow with a polydisperse evaporating spray representative of practical injections. A cloud of droplets is injected in an inert laminar round jet, axisymmetr...

In spark-ignition engines, cyclic variability limits the optimisation of operating conditions (choice of spark advance and/or injection timing) since it induces load variations and the occurrence of misfire and/or knock. This, in turn, restricts the operation range of new concepts such as downsizing or stratified combustion. To understand the basic...

This paper describes a compressible Large Eddy Simulation (LES) used to investigate cyclic variations for nonreacting flow in an optical single cylinder engine setup. The simulated operating point is part of a large experimental database designed to validate LES for cycle-to-cycle prediction, and constitutes a first step towards the realization of...

In the present contribution, we consider acoustically pulsated free jets with a polydisperse spray injection in an axisymmetrical configuration. The acoustic excitation creates periodical large vortical structures, which are representative of the dynamics of gaseous flows in more complex configurations, and a strong interaction with the injected sp...

This paper presents an experimental study of the ef fect of air preheating temperature on the main feat ures of mild flameless combustion obtained in a laboratory-scale furnace. Mild flameless combustion regime is conse rved whatever the air temperature varying from 838 K to ambient value. No visible flame is observed. Main a erodynamic features of...

Phenomena responsible of partially premixed laminar flame stabilization are investigated on a rich premixed burner configuration. The structure and aerodynamics of the flame generated by a cooking model burner are characterized by Planar Laser Induced Fluorescence of OH radical and Particle Image Velocimetry. The flame behaviour is studied from a s...

The accurate simulation of the dynamics of polydisperse evaporating sprays in unsteady gaseous flow with large scale vortical structures is both a crucial issue for industrial combustion application and a challenge for modelling and scientific computing. Various appraoches have been developped in order to resolve the dispersed liquid phase starting...

This paper presents an experimental study of flameless mild combustion in a laboratory-scale furnace. OH* chemiluminescence imaging shows that the main reactive zone is lifted off in the mixing layers of the central air jet and each coplanar methane jets. Aerodynamic features leading to the mild combustion regime are identified from PIV measurement...

Phenomena responsible of partially premixed laminar flame stabilisation are investigated on a rich premixed burner configuration. The structure and aerodynamic of the flame generated by a cooking model burner are characterized by Planar Laser Induced Fluorescence of OH radical and Particle Image Velocimetry. The flame behaviour is studied from a st...