Flame Complex Permittivity Model Considering Electrons and Positive Ions

Abstract

Flame complex permittivity is a parameter used to characterize flame electrical properties and is closely related to combustion. In order to accurately measure the parameters of the combustion state by the complex permittivity, it is crucial to analyze the flame complex permittivity model. This paper proposes a new flame complex permittivity model related to temperature, pressure, the number density of electrons, and the number density of positive ions. The distributions of temperature, electrons, and H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> in flame are obtained by Fluent imported with a CHEMKIN-format file. By combining these distributions with the proposed and previous models, the flame complex permittivity is calculated under the two models. Based on the simulation results, the experiment values of flame complex permittivity are acquired by the electric probe. Also, the temperature values of the same position are obtained by the thermocouple. The proposed model is verified through the difference analysis of experimental results between electric probes with and without positive voltage bias.