ARL-MR-586 - Toward Improving the Efficiency and Realism of Coupled Meteorological---Acoustic Computer Models for the Forest Canopy | U.S. Army Research Laboratory

摘要

Several physics-based computer models have been developed to calculate one- and two-dimensional forest canopymicrometeorology and turbulence for future U.S. Army acoustic application research. Individual computer codes haveincorporated various computational methods on a uniform grid to solve the meteorological fields. However, it may be possibleto improve the efficiency and realism of the coupled meteorological?acoustic computer models by introducing variable grid.Variable grid will allow for better distribution of grid points and will extend calculations higher into the boundary layer abovethe forest. A finer grid inside the forest and a coarser grid above the forest will help to resolve important meteorological (andacoustic) scales and processes.Therefore, the following report presents results from some preliminary tests to incorporate this important feature into numericalcodes. First, several simpler physics-based diffusion models are developed to benchmark fundamental (numerical) techniques.Both explicit and implicit differencing schemes are examined. In addition, numerical stability criteria for these calculations aredemonstrated. Then, successful preliminary tests on these codes are extended to more complicated meteorological?acousticmodels for the forest canopy.