Comprehensive modeling of ignition and combustion of multiscale aluminum particles under various pressure conditions  

作　　者：Zhenkun HU Ying FENG Wei DONG Yong TANG Jia LI Lijuan LIAO Majie ZHAO Baolu SHI 

机构地区：[1]School of Aerospace Engineering,Beijing Institute of Technology,Beijing 100081,China [2]Key Laboratory for Mechanics in Fluid Solid Coupling Systems,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China [3]Chongqing Innovation Center,Beijing Institute of Technology,Chongqing 404100,China

出　　处：《Chinese Journal of Aeronautics》2024年第11期188-202,共15页中国航空学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.U20B2018 and U23B6009)。

摘　　要：The ignition and combustion of aluminum particles are crucial to achieve optimal energy release in propulsion and power systems within a limited residence time.This study seeks to develop theoretical ignition and combustion models for aluminum particles ranging from 10 nm to 1000μm under wide pressure ranges of normal to beyond 10 MPa.Firstly,a parametric analysis illustrates that the convective heat transfer and heterogeneous surface reaction are strongly influenced by pressure,which directly affects the ignition process.Accordingly,the ignition delay time can be correlated with pressure through the p^(b)relationship,with b increasing from-1 to-0.1 as the system transitions from the free molecular regime to the continuum regime.Then,the circuit comparison analysis method was used to interpret an empirical formula capable of predicting the ignition delay time of aluminum particles over a wide range of pressures in N_(2),O_(2),H_(2)O,and CO_(2)atmospheres.Secondly,an analysis of experimental data indicates that the exponents of pressure dependence in the combustion time of large micron-sized particles and nanoparticles are-0.15 and-0.65,respectively.Further,the dominant combustion mechanism of multiscale aluminum particles was quantitatively demonstrated through the Damköhler number(Da)concept.Results have shown that aluminum combustion is mainly controlled by diffusion as Da>10,by chemical kinetics when Da≤0.1,and codetermined by both diffusion and chemical kinetics when 0.1<Da≤10.Finally,an empirical formula was proposed to predict the combustion time of multiscale aluminum particles under high pressure,which showed good agreement with available experimental data.

关 键 词：Multiscale aluminum particles Ignition delay time Combustion mechanism Combustion time PRESSURE 

分 类 号：V430[航空宇航科学与技术—航空宇航推进理论与工程]