机构地区:[1]Institute of Fluid Dynamics and Thermodynamics,Universitaetsplatz 2,Magdeburg,39106,Saxony-Anhalt,Germany [2]Interdisciplinary Centre for Advanced Materials Simulation(ICAMS),Ruhr-University Bochum,Bochum,44801,Germany [3]ONERA The French Aerospace Lab,Department of Aerodynamics,Aeroelasticity and Acoustics(DAAA),Paris-Saclay University,Meudon,92190,France
出 处:《Particuology》2024年第2期167-185,共19页颗粒学报(英文版)
基 金:funding by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)-Project-ID 422037413-TRR 287 and the technical support of Mr.Chinmay Laxminarayan Hegde in performing experiments in the lab.We are also greateful for the fruitful discussions with Gunar Boye,Seyed Ali Hosseini,Dominique Thevenin and Katharina Zahringer.
摘 要:This study investigates the interaction between a premixed methane-air flame and particles inside a model packed bed.The opacity of the spherical packed beds to visible light poses a major barrier to the implementation of highly resolved optical diagnostics,so that no detailed experimental data were so far available for the validation of numerical simulation.Here,a two-dimensional cylindrical packed bed design is set up,which enables direct line-of-sight optical measurements without loss of spatial reso-lution over the fluid region between the particles.In this study,the case of cold metallic cylindrical particles(T=377 K)relevant to start-up of a reactor is investigated using internal particle cooling,which also allows cylinder specific heat transfer rate measurements by differential temperature measurements on the coolant streams.The two dimensional assumption is first verified by measuring the inflow ve-locity and cylinder temperature profile along the cylinders.Chemiluminescence imaging is then per-formed using a telecentric lens to observe the position and geometry of the two-dimensional flame front with respect to the surrounding cylinders without loss of resolution.Simultaneously,the cylinder-specific flame to cylinder heat transfer rates and cylinder surface temperature are measured.As the flame is closely surrounded by the three cooled cylinders,intense heat transfer is observed in this region corresponding to 25±2.5%of the flame thermal power.Flames were stabilised at different positions depending on inflow velocity and equivalence ratio,and a direct correlation between flame to cylinder stand-off distance and the heat transfer rate normalised to the flame thermal power was found for both top and side cylinders.Also,sidewall quenching distances to the curved cylinder surfaces were evaluated,and seem to be influenced by the presence of a warm recirculation zone behind the cylinders.This investigation provides fully resolved flame front position and heat transfer rates for a known geometry and cylinder t
关 键 词:Packed beds Flame-particle interaction Optical diagnostics Sidewall quenching
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