Enhancements to AERMOD's building downwash algorithms based on wind-tunnel and Embedded-LES modeling

Abstract

Knowing the fate of effluent from an industrial stack is important for assessing its impact on human health. AERMOD is one of several Gaussian plume models containing algorithms to evaluate the effect of buildings on the movement of the effluent from a stack. The goal of this study is to improve AERMOD's ability to accurately model important and complex building downwash scenarios by incorporating knowledge gained from a recently completed series of wind tunnel studies and complementary large eddy simulations of flow and dispersion around simple structures for a variety of building dimensions, stack locations, stack heights, and wind angles. This study presents three modifications to the building downwash algorithm in AERMOD that improve the physical basis and internal consistency of the model, and one modification to AERMOD's building pre-processor to better represent elongated buildings in oblique winds. These modifications are demonstrated to improve the ability of AERMOD to model observed ground-level concentrations in the vicinity of a building for the variety of conditions examined in the wind tunnel and numerical studies.

Numerical analysis of pollutant dispersion around elongated buildings: An embedded large eddy simulation approach

“…Future research will focus on using this CFD-based "virtual test-rig" constrained by wind tunnel data (see Perry et al, 2016) to examine the building downwash phenomena for a much greater variety of building shapes, stack heights, and locations. Ultimately, the data from these simulations, along with relevant data from the previous and current wind-tunnel measurements, will be used to thoroughly analyze the flow and dispersion around buildings and to help develop improved parametrizations (see Monbureau et al, 2018). Computational grid on a vertical plane at y/H=0 for case A; the whole domain (left) and mesh details near the stack and source (right).…”

“…AERMOD) ability to accurately model complex building downwash scenarios. We have documented our effort in this context in an accompanying manuscript recently published (Monbureau et al, 2018). With comprehensive velocity and concentration fields, an examination of plume growth, plume trajectory, and the pollutant fluxes between various flow regions is possible to a degree not feasible with wind tunnel measurements alone.…”

Estimation of air pollutants emission (PM10, CO, SO2 and NOx) during development of the industry using AUSTAL 2000 model: A new method for sustainable development

“…Other gases are often produced by fuel combustion [18]. Dispersion of such contaminants from high level stacks has a significant impact on their emissions at the ground surface around the factory [19,20].…”