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| Numerical analysis of aerosol deposition onto horizontal surfaces by combined mechanisms |
| WU Shi-xian1, ZHU Hui2, QI Can1, KANG Yan-ming2 |
1. Department of Building Environment and Energy Engineering, Guilin University of Aerospace Technology, Guilin 541004, China;
2. School of Environmental Science and Engineering, Donghua University, Shanghai 201620, China |
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Abstract A discrete stochastic model was developed to simulate deposition of aerosol particles onto horizontal solid surfaces. Lattice walk method was employed to solve particle-transport-equation, which allowed obtaining the trajectory of particle motion by combination of migration by external field and diffusion in the calculation domain. The local structures of deposited particles forming dust layer, the relationship between structure of dust layer and mechanisms of particle transport, and the number of the particles attached to a horizontal surface were investigated. The results showed that for low values of Peclet number, when diffusion was a controlling mechanism of aerosol transport, dust layers might exhibit more open and looser structures, while the layer structures were dense and tight at high values of Peclet number. Differences of aerosol deposition morphology between different transport mechanisms were caused by different random intensities of particle motion. Additionally, there was an upper limit of the maximum number of particles attached to the surface, and it strongly depended on particle transport mechanisms and size distributions.
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Received: 25 June 2015
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