An Uncertainty Quantification Analysis in a Simplified Problem of Urban Pollutant Dispersion by Means of ANOVA-POD/Kriging-Based Response Surfaces

In the last decade there has been a growing interest in urban flow CFD simulations. As RANS approaches demonstrated to be not enough accurate to predict urban flows, people focus more and more on LES simulations. Though better results could be obtained with fine grid LES, the complexity of the urban physics seems to vanish the increasing computational resources. A different approach is herein considered, proposing a first uncertainty quantification (UQ) analysis on a single building pollutant dispersion case. A hybrid method merging the anchored-ANOVA and the POD/Kriging-based response surface is proposed to reduce the costs of the UQ analysis. Moreover, simulations are performed by the Lattice Boltzman (LBM) code PowerFLOW. Sensitivity results are presented showing the importance of vortex dynamics and the high sensitivity to the wind angle.