Local and urban scale modeling - Air Pollution Modeling and Its Application - page 58

References
Arnold, S. J., et al. 2004. Introduction to the DAPPLE Air Pollution Project. Science of The Total
Environment. 2004, Vol. 332, pp. 139-153.
Bentham, T. 2003. Microscale modelling of air flow and pollutant dispersion in the urban
environment. Imperial College London Thesis. 2003.
Mansoorzadeh, S., et al. 1998. Finite element simulations of incompressible flow past a
heated/cooled sphere. International Journal for Numerical Methods in Fluids. 1998, Vol. 28,
pp. 903-915.
Pain, C. C., et al. 2001. Tetrahedral mesh optimisation and adaptivity for steady-state for transient
finite element calculations. Computer methods in applied mechanics and engineering. 2001,
Vol. 190, pp. 3771-3796.
Pavlidis, D., et al. 2009. Synthetic Eddy Method for Regional Atmospheric Flows. Boundary
Layer Meteorology. 2009, Vol. In preparation.
5. Questions and Answers
Question: One feature of your model is to include traffic induced turbulence. For
very busy roads the traffic is not steady, but stops and starts in a complex way.
Can this be included in your model?
Answer: Yes, it can be and it is included. Traffic induced turbulence is modeled
through a two-fluid approach. Individual vehicles are explicitly modeled. Their
movement is controlled by a traffic micro-simulation model. An interface
between Fluidity and PTV-VISSIM has been built. Depending on the scenario
considered each time, the traffic can be steady or, complex and vehicle
clustering is evident.
Question: The title of your presentation was LES but you conclude that you
presented a CFD model. The difference in the naming is not clear since LES
and CFD are not always the same. (Tamir Reisin)
Answser: LES is just a closure technique for high Reynolds number flows for the
Navier-Stokes equations. LES is a CFD method.
Question: Please clarify whether you have been using a RANS-CFD or an LES
approach for your study. (Silvia Trini Castelli)
Answer: I have been using LES. As I mentioned earlier, LES is a scheme for
efficiently solving the Navier-Stokes equations for turbulent flows, thus the
LES method is a CFD method.