J3.4
Dispersion around an L-Shape building: comparisons between wind tunnel data and the RUSTIC/MESO models
Steve Diehl, ITT Industries/Advanced Engineering and Sciences, Colorado Springs, CO; and D. A. Burrows and E. Hendricks
ITT Industries, Advanced Engineering and Sciences has developed two models to predict air flow and dispersion in urban environments. The first model (RUSTIC) is a fast running urban air flow code that rapidly converges to a numerical solution to a modified set of the compressible Navier-Stokes equations. The model also includes a k-ù turbulence model and atmospheric stability. The second model (MESO) is a mesoscale Lagrangian particle transport and diffusion code that can predict concentrations of a released chemical or biological agent.
As a preliminary validation of the models, concentrations predicted by MESO are compared to experimental data from a wind tunnel test (Cowan, Castro and Robbins 1995). A brief overview of the wind tunnel test is as follows. First, a 1:200 full scale model of an L-shaped building is placed in a wind tunnel and the building is oriented at both 0° and 45° to the impinging wind. Then a neutrally buoyant tracer gas is emitted from a door in the building, and concentrations of this gas are measured at a lateral cross section downwind from the building.
RUSTIC/MESO is setup with the initial conditions of the wind tunnel experiment, and the steady-state concentrations predicted by the models are compared to the wind tunnel data at this lateral cross section. At most heights, a favorable comparison is seen for both concentration magnitudes and lateral distribution of the gas; validating the models in this idealized scenario.
Joint Session 3, Building Scale Dispersion (Joint between the Fifth Symposium on the Urban Environment and the 13th Conference on the Applications of Air Pollution Meteorology with the A&WMA) (parallel with sessions 9 and J4)
Wednesday, 25 August 2004, 10:30 AM-11:45 AM
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