表面粗糙度对APS-YSZ涂层传热特性和冷却气膜流动行为的影响  

Effect of Surface Roughness on Heat Transfer of APS-YSZ Coatings and Cooling Gas Film Flow Behavior

作　　者：桑润轩 龙芸 陈小虎 王玉璋[1] SANG Runxuan;LONG Yun;CHEN Xiaohu;WANG Yuzhang(School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学机械与动力工程学院,动力机械与工程教育部重点实验室,上海200240

出　　处：《工程热物理学报》2022年第12期3364-3373,共10页Journal of Engineering Thermophysics

基　　金：国家科技重大专项(No.2017-V-0011-0063);上海汽车工业科技发展基金(No.1741)。

摘　　要：由于大气等离子喷涂(APS)钇稳定氧化锆(YSZ)热障涂层的材料与工艺问题,在制备完成后其表面往往存在一定粗糙度,这种粗糙度在服役过程中会因涂层的退化行为而发生改变,并对冷却气膜的流动行为与涂层的换热特性造成影响。本文基于快速傅里叶变换算法(FFT)与孔隙-裂纹-颗粒微观结构重建算法(PCPMR)对含不同表面粗糙度(R_(q)=0.0~10.0μm)的热障涂层模型进行了数值重构,基于双分布函数格子玻尔兹曼算法(DDF-LBM)研究了含粗糙度的热障涂层表面的换热特性与附近气膜的流动特性。研究表明,粗糙度使冷却气膜的速度边界明显上移,在粗糙结构周围产生涡结构,法向速度波动增大,流动稳定性降低。粗糙度增大了涂层表面的温度不均匀性与换热强度。相比平滑涂层,R_(q)=10.0μm的粗糙度使涂层表面摩擦力增大20.67%,对流换热强度提高12.02%,这将恶化涂层的隔热性能,缩短其服役寿命。Due to the material and preparation process, the surface of air plasma sprayed(APS)yttria-stabilized zirconia(YSZ) thermal barrier coating often has roughness, which will change with the degradation of the coating during service. The roughness will affect the flow behavior of the cooling gas film and the heat transfer characteristics of the coating. In this paper, fast Fourier transform method(FFT) and pore-crack-particle microstructure reconstruction method(PCPMR) were used to reconstruct the thermal barrier coating model with different surface roughness(R_(q)=0.0~10.0 μm).The heat transfer characteristics of the thermal barrier coating surface and the flow characteristics of the nearby gas film were numerically studied based on double distribution function(DDF) lattice Boltzmann method(LBM). The results show that the rough structure leads to vortex and obviously moving up of velocity boundary. It increases the maldistribution of temperature and heat transfer intensity of the coating surface. Compared with the smooth coating, the roughness of R_(q)=10.0 μm increases the surface friction by 20.67% and the convective heat transfer intensity by 12.02%, which will lead to the deterioration of the insulation performance and service life of the thermal barrier coating.

关 键 词：热障涂层 表面粗糙 DDF-LBM 流动换热 

分 类 号：TK221[动力工程及工程热物理—动力机械及工程]