Study on oxygen transport and titanium oxidation in coating cracks under parallel gas flow based on LBM modelling  

作　　者：Shengfeng Luo Song Zhang Yiping Zeng Hui Zhang Lili Zheng Zhaopeng Xu 

机构地区：[1]Department of Engineering Physics,Tsinghua University,Beijing 100084,China [2]Department of Mechanics and Aerospace Engineering,Southern University of Science and Technology,Shenzhen 518055,China [3]Institute for Aero Engine,Tsinghua University,Beijing 100084,China [4]Shenzhen Smart Hua Information Technology Research Co.,Ltd.,Shenzhen 518000,China [5]School of Aerospace Engineering,Tsinghua University,Beijing 100084,China [6]Chinese Academy of Agricultural Mechanization Sciences,Beijing 100084,China

出　　处：《Chinese Journal of Chemical Engineering》2023年第4期15-24,共10页中国化学工程学报（英文版）

基　　金：supported by National Science and Technology Major Project (2017-VII-0012-0108);National Key Research and Development Program of China (2016YFB1102302);China Postdoctoral Science Foundation (2019M660664);National Natural Science Foundation of China (72004141);Basic and Applied Basic Research Foundation of Guangdong Province (2019A1515111074)。

摘　　要：The oxygen transportation from surrounding air to coating cracks is an important factor in the oxidation and ignition of titanium alloy. In this work, the oxygen transport and surface oxidation of titanium in inclined cracks of coating under parallel airflow are studied with the lattice Boltzmann method(LBM).A boundary scheme of LBM about surface reaction is developed. The conversion factors are utilized to build the relationship between the physical scale and the lattice scale. The reliability of the LBM model is validated by the finite element method(FEM). The results show that the convective mass transport driven by the surrounding airflow and the vortex structure formed inside the crack are the two significant factors that influence the oxygen transport in cracks. The convective mass transfer plays a major role in oxygen transport when the inclination angle of the crack is small. For the cases with a large inclination angle, the oxygen transfer from the top to the bottom of the crack is mainly controlled by mass diffusion mechanism. The oxygen concentration in inclined cracks is generally less than that in vertical cracks, and oxidation and ignition of the substrate titanium might be more likely to occur in relatively vertical cracks.

关 键 词：Coating crack OXIDATION Transport IGNITION Numerical simulation 

分 类 号：TG174.4[金属学及工艺—金属表面处理]