AirWare Reference Manual: Computational kernel

AirWare On-line Reference Manual

Release Level	5.3.0 beta
Release Date	2007 06
Revision Level	1.1

Computational kernel

The high-resolution near field dispersion model for line sources (traffic) used is based on AERMOD, and uses a computational kernel based on an area source (Gaussian solution with an hourly aggregation period) with a mixing zone approach in and over the street itself with unit emissions. The mixing zone approach representrs the high turbulence over and near the street itself, due to

the energy budget of asealed street surfaces;
the turbulent mixing caused by the moving traffic itself.

The kernel results are then scaled according to actual traffic frequency, speed, and fleet composition, and distributed along the line sources by a convolution method.

The kernel is defined in terms of its resolution (default: 10m) and size (1-5 km), and the mixing zone parameters, expressed as a set of symbolic choices of algorithms.

The kernel is linked to

individual line sources, where the model is run for a single hour;
AERMOD scenarios, where the traffic part is computed with the convolution method based on the kernel, which is generated for 24 subsequent hours for a complete AERMOD 24 hour scenario.

In the latter case, the 24 kernel solution are using the actual hourly meteorological data, and the results can be viewed under an animation tape deck control.