Explicit stochastic schemes for transport in particle-resolved simulations

Particle-resolved methods;Particle transport;Stochastic methods

Nuwal, Nakul ; Sayadi, Taraneh ; Riemer ; Nicole ; West ; Matthew

关键词: Particle-resolved methods;    Particle transport;    Stochastic methods;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/92971/NUWAL-THESIS-2016.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Stochastic particle-resolved methods are a recent development in atmospheric aerosol modeling. These methods resolve individual aerosol particles to track the information of their composition during a numerical simulation. This enables the detailed analysis of aerosol and gas-phase chemistry, and allows for a more accurate estimate of the aerosol impact on human health and Earth's climate. Transport of all particles in afinite-volume framework can be represented as a stochastic model with each particle having a probability to commute between neighboring grid-cells. This work develops and illustrates the stochastic particle-resolved transport method, which can be used for aerosol transport in atmosphere. The development of the stochastic model was inspired by the passive scalar transport in a predefined velocity field. The model was developed by splitting the transport process into advection and diffusion, and combining them with superposition. Single time-step explicit advection schemes and a Range-kutta numerical scheme were compared to the deterministic advection equation solutions and analytical solutions. The analysis also includes the stochastic modeling of the diffusion process and its results compared to analytical solution. For all cases, a quantification of total error and a numerical convergence analysis is presented.