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Showing 1 to 16 of 16 for “"reactive flows"”.
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Gaseous Reactive Flows Around Catalytically Combusting Micro-Wires
The reactive flow around catalytically coated cylinders was investigated experimentally in the regime of Reynolds and Peclet numbers that are relevant to small-scale power generation. Methane and propane combustion was established on the surface of the catalyst by placing a small-diameter wire in …
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Mesoscopic Numerical Methods for Reactive Flows: Lattice Boltzmann Method and Beyond
Reactive flows are ubiquitous in several energy systems: internal combustion engines, industrial burners, gas turbine combustors. Numerical modeling of reactive flows is a key tool for the development of such systems. However, computational combustion is a challenging task per se. It generally …
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Hybrid Eulerian/Lagrangian 3D methods for high Reynolds number reactive flows
… and multiphysics nature of the underlying flows. This thesis presents progresses in combustion modeling for the numerical simulation of turbulent reactive jet flows through the design of a hybrid Eulerian/Lagrangian and massively parallel 3D numerical simulation tool. The adaptivity of the …
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CFD-DEM MODELLING OF PARTICLE-GAS REACTIVE FLOWS AND ITS APPLICATION IN BLAST FURNACE REGIONS
… blast furnace involves complex particle-gas reactive flows, which are crucial for determining the efficiency and effectiveness of iron production. A fundamental understanding of these intricate reactive flows is essential for optimizing furnace operation and performance. This thesis presents …
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Development of a multi-scale projection method with immersed boundaries for chemically reactive flows and its application to examine flame stabilization and blow-off mechanisms
… spatio-temporal scales associated with reacting flows around immersed boundaries, and (ii) to use this tool to investigate the underlying mechanisms of flame stabilization and blow-off in canonical configurations. A second-order immersed boundary method for reacting flow simulations near heat …
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Parameter estimation and optimal experimental design in flow reactors
… the finite element method, for the simulation of reactive flows in a chemical flow reactor as well as for the identification of the kinetic of the reactions using measurements of observable quantities. We present the case of a real experiment in which the reaction rate is estimated by means of …
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Adaptive Finite Element Computation of Chemical Flow Reactors
… chemical and physical processes taking place in reactive flows, many chemical species are to be considered with often a few hundred elementary reactions. Thus the system of equations modelling the reactive flow usually contains between 10 and 50 equations and is highly non-linear. We develop in …
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Experimental investigation of the flow field during combustion in narrow circular ducts
… determine the structure of these oscillatory reactive flows. It was established that the flow was essentially one-dimensional with little curving of the flow tube only near the flame front. Entropy generation from vorticity was negligible when compared with the entropy produced from combustion …
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Experiments on the dynamics of buoyancy-driven flows in reactive porous media
Reactive flows in porous media are of great interest to a number of geological and industrial situations where fluid of one composition invades a formation containing a solid component with which it can react. Geological situations include dolomitisation of limestone following invasion of sea water …
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Non-linear reduced order modeling for transport dominated fuid systems
… methodology enables the decomposition of reactive systems with topologically changing front structure, such as splitting or merging reaction fronts, that pose difficulties for many non-linear reduction methods. The last part studies the ability of the non-linear reduction methods to …
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Modeling the flow of non-Newtonian fluids in packed beds at the pore scale
… modeling is required for certain non-linear flows, such as multi-phase flows, inertial flows, non-Newtonian flows, and reactive flows. Pore-scale modeling is a first-principles approach to modeling flow and transport in porous media. In this work, network models that are physically …
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Simulations of turbulent swirl combustors
… The first study investigates isothermal air flows behind an enclosed bluff body, with the incoming flow being pulsated. These flows have strong similarities to flows found in combustors experiencing self-excited oscillations and can therefore be considered as canonical problems. At high …
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Collaborative Simulation of Reacting Flow and Controller in Chemical Looping Systems
… in energy-intensive industries, where multiphase reactive systems are highly dynamic and sensitive to fluctuating conditions. Among these, chemical looping technologies, including chemical looping combustion (CLC) and chemical looping gasification (CLG), stand out as promising solutions for carbon …
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Mixing and Evaporation at the Cloud Edge and Angular Dynamics of Small Crystals in Viscous Flow
How liquid water in atmospheric clouds distributes over droplets of different sizes is important for the initiation of rainfall, and for the optical properties of the atmosphere. Droplet-number densities and droplet-size distributions change rapidly at turbulent cloud edges, where mixing of cloudy …
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Fluid dynamics of boundary layer combustion
Reactive flows within a boundary layer, representing a marriage of thermal, fluid, and combustion sciences, have been studied for decades by the scientific community. However, the role of coherent structures within the three-dimensional flow field is largely untouched. In particular, little …
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Internal energy relaxation in nitrogen plasmas
This work discusses the chemical kinetics of nitrogen molecules relaxing in a heat bath at constant temperature in a background gas composed of electrons and nitrogen atoms. The QCT (Quasi-Classical Trajectory) model recently developed at NASA Ames Research Center is used to study energy transfers …