Outdoor aerosol processes are often associated with disasters and diseases,which threaten human life and health.Outdoor aerosols are afluid system affected by meteorological conditions and three-dimensional complex te...Outdoor aerosol processes are often associated with disasters and diseases,which threaten human life and health.Outdoor aerosols are afluid system affected by meteorological conditions and three-dimensional complex terrain.Their variable wind speed and direction and complex terrain boundary conditions make simulating advection processes difficult.Based on incompressibleflow conditions,we designed an adaptive time step algorithm for forward advection for the rapid simulation of aerosol processes.The method is based on thefirst-order forward semi-Lagrangian advection method with unconditional mass conservation.Thefirst-order truncated error coefficient function theory generates an adaptive time step to control the accuracy of forward advection.Smoke aerosol simulation experiments in two small outdoor scenes were designed,and the effects of the traditional backward advection and forwardfixed step methods were compared with the algorithm in this study.The proposed simulation method showed improved accuracy compared with the other two methods in experimental scenarios;moreover,compared with those of the traditional backward method,the computation time was significantly reduced and the conservation of mass was significantly improved.Thus,the proposed method is a fast simulation method for outdoor aerosol numerical prediction.KEY POLICY HIGHLIGHTS.The first-order forward semi-Lagrangian method,which requires no iteration and less computation and offers unconditional conservation,was used..The law of truncation error coefficient of thefirst-order forward method was studied and an adaptive step algorithm was designed..Full-size real aerosol experiments in small-scale complex outdoor scenes were conducted for verification and comparison of simulation effects.展开更多
基金supported by National Key Research and Development Program of China [grant numbers 2020YFF0400405].
文摘Outdoor aerosol processes are often associated with disasters and diseases,which threaten human life and health.Outdoor aerosols are afluid system affected by meteorological conditions and three-dimensional complex terrain.Their variable wind speed and direction and complex terrain boundary conditions make simulating advection processes difficult.Based on incompressibleflow conditions,we designed an adaptive time step algorithm for forward advection for the rapid simulation of aerosol processes.The method is based on thefirst-order forward semi-Lagrangian advection method with unconditional mass conservation.Thefirst-order truncated error coefficient function theory generates an adaptive time step to control the accuracy of forward advection.Smoke aerosol simulation experiments in two small outdoor scenes were designed,and the effects of the traditional backward advection and forwardfixed step methods were compared with the algorithm in this study.The proposed simulation method showed improved accuracy compared with the other two methods in experimental scenarios;moreover,compared with those of the traditional backward method,the computation time was significantly reduced and the conservation of mass was significantly improved.Thus,the proposed method is a fast simulation method for outdoor aerosol numerical prediction.KEY POLICY HIGHLIGHTS.The first-order forward semi-Lagrangian method,which requires no iteration and less computation and offers unconditional conservation,was used..The law of truncation error coefficient of thefirst-order forward method was studied and an adaptive step algorithm was designed..Full-size real aerosol experiments in small-scale complex outdoor scenes were conducted for verification and comparison of simulation effects.
