Low quality gases, also called Low NCV gases, generated by industrial processes or waste recovering are today widely seen as a source of energy. Typical examples gases are biogas produced by vegetables waste fermentation, synthetic gases generated by biomass gasification (at ambient pressure or in pressurized conditions), Coke Oven Gases (COG) and Blast Furnace Gases (BFG) resulting from steelmaking operations and all sources of CO/CO2/CH4 mixtures emitted by various chemical industries (i.e. oil refinery). In steelmaking plant, low NCV fuels that consist in CO/H2/CH4/CO2/N2 mixtures are burnt with air and additional gas (methane, propane,…) in steam turbines for getting heat, gas turbines for making power, motors for providing mechanical energy or simply in flares at elevated height for avoiding poisoning the urban atmosphere. Limited efficiency, NOx emissions, incompatibility to CCS solution (nitrogen in air), low flexibility equipment are some drawbacks of air combustion that can be improved by substitution with pure O2 combustion. The objective of the project is to develop an oxy-burner that can work with any composition of low NCV fuel without additional methane (as existing today) and especially for specific workshops of steelmaking industry that wants to burn mixture of blast furnace gases that have variable composition. To avoid this extra fuel and to enhance combustion efficiencies, the innovation consists in preheating the oxygen and low NCV fuel that is known to ensure a better self-ignition and thus stabilized flame. Phenomenological study, development of an industrial scale the technology and application at an industrial scale are the main tasks of the project. This innovative technology valuable for steelmaking industry will be opened to any process using low NCV gases as an alternative to meet sustainable growth targets.

The prediction of damage caused by blast waves, generated by large scale explosions or industrial hazards (accidents in industrial systems or storage units) is an important technological and research problem that needs further understanding from disaster prevention point of view. The ERANE project has two main important goals: (1) to understand the complex physical phenomena induced by blast and shock waves that pass through complex media (buildings, industrial plants, topographic reliefs, slopes, river valley, etc.) and (2) to help designing new devices for protection against shock and blast loading in an urban agglomeration.

The REFINE project focuses on the experimental investigation and numerical simulation of real-fluid injection and mixing processes under sub-, trans- and super-critical conditions. The domain of interest of the present proposal concerns the propulsion with application to the automotive and aerospace science and technology where supercritical fluids may be considered as propellants. Indeed, the need for higher efficiency and lower emission levels leads to increase pressure and temperature levels, i.e. to reach supercritical properties of fluids. The objective of REFINE is to build a simple well-controlled test-bench able to study a fluid injection under sub-, trans- and super-critical conditions and to associate experimental and numerical diagnostics to deliver the finest information. An ethane injection occurs in a 5-liter high-pressure experimental test-bench. The X-ray diagnostics setting-up will be the project keystone, as it allows for delivering a non-polluted density measurement. Indeed, such diagnostics are not disrupted by the index gradient observed in corrugated flows, contrary to laser techniques. Colored background oriented Schlieren visualization is used for backup as well as a more classical shadowgraphy technique. Numerical simulations will be realized in parallel to consolidate physics understanding and for model validation.

Soot particles are formed during the combustion of hydrocarbon/air mixtures in most combustion devices related to transportation. They are regulated for Diesel engines, and will soon be for spark-ignition (SI) engines and gas turbines (GT). These regulations will concern not only the soot mass emission, but also the number of particles and finally the number of the smallest (most harmful) ones. Diesel engines are today equipped with particle filters (PF) that allow to suppress particles at the engine exhaust. On the contrary, reducing soot emissions at the source could avoid fitting SI engines with PF, as is the case today. Even if a PF is used, there still is a strong interest in reducing soot emission at the source for Diesel and SI engines because this would allow improving the fuel efficiency and to reduce the high cost of after-treatment systems. In the aeronautical domain, reduction at the source is the unique way to reduce soot emissions. In this context, engine manufacturers of piston engines (PE) and aircraft GT will need reliable experimental and numerical tools to evaluate both the total soot volume fraction (SVF), as well as the Soot Number Density Function (SNDF) at the engine exhaust. Besides, due to the scarcity of fossil fuels, the contribution of bio-sourced fuels will become dominant in the future. A key issue is then to be able to evaluate the impact of fuel formulation on soot emissions. The objective of ASMAPE is the development of validated predictive Computational Fluid Dynamics (CFD) models for the formation and evolution of soot during the turbulent combustion processes, in both PE and GT. The ambition is to address the three main commercial fuels (CF) relevant for a present usage: Gasoline, kerosene and Diesel fuel. The predictive capability of the models to be developed will concern both the SVF and SNDF. The originality of ASMAPE is to propose an innovative integrated research work bringing together advanced optical diagnostics, chemical kinetics and turbulent combustion modelling, as well as work on numerical methods, applied to a wide spectrum of studies ranging from basic laminar flames to real-size PE and GT. The starting point will be the acquisition of a well defined sooting laminar flames experiments using advanced optical diagnostics, and its analysis in order to gain detailed insight into the chemistry of polycyclic aromatic hydrocarbons (PAH) and soot nucleation, and to develop surrogate fuel (SF) chemical mechanisms able to predict them for the CF considered. The proposed mechanisms will then be exploited in order to formulate a sectional and an alternative pretabulated soot model, available in the project's CFD codes. Presently, they rely on ad-hoc soot gas phase chemistry and are thus strongly limited in terms of predictive capabilities. ASMAPE aims at improving them by developing methods for accurately coupling the soot models with the turbulent combustion models used for the different applications within the project. This modelling work will concern both RANS codes for PE and GT, and a LES research code widely used in both domains. Furthermore, the acquisition of two experimental databases on turbulent sooting flames will provide reliable data for extensively validating the project's soot models. The capacity of these models to predict soot formation and evolution in real-size PE and GT will be demonstrated at the project end. Finally, work will be undertaken in the view of extending the predictive capacities of future soot models to cover not only the SVF and SNDF but also aspects as particle shape or composition, while reducing the related CPU time overhead. The developed CFD soot models will directly be available at the project end for the French automotive and aeronautical industry to support design work aimed at limiting soot production at the source.

The project deals with optical properties of droplets and particles of “complex” shapes, and whose sizes are beyond a few visible light wavelengths. In this domain, rigorous theories and existing numerical methods cannot be applied to accurately describe light scattering phenomena. We propose a new methodology to calculate the interaction of light with such objects, in parallel to a series of experimental tests for validation. The project includes novel applications in optical metrology, and in optical trapping and manipulation of non spherical particles. Complex-shaped particles (CSP) are everywhere present in fluid mechanics problems (multiphase flows, sprays, aerosols..), chemical engineering and life science. Attempts to characterize particles in flows exploit their far-field light scattering properties (laser diffractometers, phase Doppler interferometers and particle imaging techniques are standard). Light scattering is also the source of the radiation pressure acting on a particle in a laser beam. The involved forces and torques make possible laser trapping (optical tweezers) and contact-less manipulation, a technique of ever growing importance in biophysics and micro technologies. Modeling the interaction of light with particles is essential. Many theories and models (scattering, absorption, radiation pressure) have been developed accordingly. Rigorous methods are limited (for theoretical or numerical reasons) to simple shape particles, i.e. spheres and cylinders, and then cannot deal with CSPs. Different numerical methods such as T-matrix, DDA , MoM and FDTD allow calculating the scattering properties of arbitrarily shaped particles, but their applicability is limited to sizes not more than a few tens of wavelengths, even with supercomputers. Thus, there is currently no accurate method to predict the light scattering properties of CSPs of sizes larger than a few tens of microns! This is the crux of AMO-COPS project: developing a novel model for large CSPs. Ray tracing, or geometrical optics, is flexible in terms of particle shapes. However ray models completely or partially neglect wave effects in general and contributions of high order rays. Recently, Partner 1 has successfully introduced wave properties in the ray model and developed a mathematical formalism that allows describing wave front curvatures and phase shifts due to focal lines. This approach, called “Vectorial Complex Ray Model” (VCRM), permits to compute precisely the scattering of a wave by large CSPs of smooth surfaces. VCRM has been applied to 2D scattering of ellipsoidal particles and elliptical cylinders. As a further contribution, the promoters of this project have proposed methods to include forward diffraction by Heisenberg’s uncertainty principle and near-critical-angle scattering effects in the model. The central goal of the project is to offer a generalized version of these works, to be cast into a general “Ray Theory of Wave” (RTW). Objectives of the project are: (1) Extension of VCRM to 3D CSPs and for various shaped beams; (2) Modeling of wave effects; (3) Prediction of radiation pressure forces and torques for CFPs; (4) Theoretical and experimental validation of RTW; (5) Application to optical characterization instruments and experimental tests on sprays and bubbly flows; (6) Manipulation and trapping of non spherical particles. The deliverables of AMO-COPS project will be computation software for prediction of optical forces, scattering properties of CFPs, and simulation of experimental characterization tools. We also anticipate providing various original theoretical and experimental results. PhD students will be trained to research throughout the project. Special attention will be paid to valorization through publications, software licenses and patents. Looking forward to the future, we expect potential applications of RTW well beyond the particular systems to be investigated in this 4-year program.