10 and Warburton et al. [11], which all focused on the modeling of nano-scale ALD process and substrate surface transitions. Based on such kind of works, the surface chemistry models are devel- oped, where the elementary reaction rates are calculated by the obtained adsorption and reaction energetics as well as the transi- tion-state configuration data. In this field, Deminsky et al. [12] developed the reaction kinetics model of zirconium and hafnium oxide film growth within the ALD reactor. Travis et al. [13,14] pro- posed a surface film growth model to investigate the ALD film growth as a function of various process parameters. These models can fundamentally reveal ALD process on the substrate surface and the related chemical kinetics. However, they have neglected the complicated transport process inside the ALD reactor chamber. Holmqvist et al. [6,15–17] presented a series of works on the Zn(C2H5)2–ZnOALDprocess,wheretheydevelopedamulti-physics model by considering both the detailed gas-surface reactions and the continuum gas flow. Such kind of detailed modeling can systematically investigate the real operation process. Due to the different surface reaction mechanisms and cycle manner, the modeling study of alumina deposition process also requires the coupling of surface reactions and cross-flow in the ALD reactor. However, to the best of our knowledge, none has been conducted yet.