This study was conducted to investigate the characteristics of meso-scale combustion.The technique of electrical capacitance tomography(ECT) was used to locate flame position and monitor the effect corresponding to varied air/fuel ratio in a meso-scale combustor.Combustion phenomena including igniting,quenching and unsteady combustion have been visualized using ECT.The method of metallization protecting ECT sensor from high temperature damage and the novel calibration method adapted to ECT monitoring of unknown permittivity flame have been shown to be successful.At the same time,electrical nature of combustion and dielectric characteristics of hy-drocarbon flame were studied.The relationship between flame permittivity and state parameters of combustion gas was demonstrated preliminarily.
Identifying the flow patterns is vital for understanding the complicated physical mechanisms in multiphase flows.For this purpose,electrical capacitance tomography(ECT) technique is considered as a promising visualization method for the flow pattern identification,in which image reconstruction algorithms play an important role.In this paper,a generalized dynamic reconstruction model,which integrates ECT measurement information and physical evolution information of the objects of interest,was presented.A generalized objective functional that simultaneously considers the spatial constraints,temporal constraints and dynamic evolution information of the objects of interest was proposed.Numerical simulations and experiments were implemented to evaluate the feasibility and efficiency of the proposed algorithm.For the cases considered in this paper,the proposed algorithm can well reconstruct the flow patterns,and the quality of the reconstructed images is improved,which indicates that the proposed algorithm is competent to reconstruct the flow patterns in the visualization of multiphase flows.
