252 Progress in Computational Fluid Dynamics, Vol. 10, No. 4, 2010 Prediction of second-order concentration statistics for dispersing plumes in obstacle arrays Bing-Chen Wang* Department of Mechanical and Manufacturing Engineering, University of Manitoba, Winnipeg, R3T 5V6, MB, Canada Fax: (204) 275-7507 E-mail: bc_wang@umanitoba.ca *Corresponding author Eugene Yee Defence R&D Canada – Suffield, P.O. Box 4000, STN Main, Medicine Hat, AB, T1A 8K6, Canada E-mail: eugene.yee@drdc-rddc.gc.ca Fue-Sang Lien Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada E-mail: fslien@mecheng1.uwaterloo.ca Abstract: In this paper, the turbulent dispersion of a passive scalar released from a continuous ground-level point-source in two obstacle arrays is simulated using the Reynolds-averaged Navier-Stokes (RANS) method. An explicit algebraic nonlinear turbulent stress model and a tensor-diffusivity scalar-flux model are used for the closure of the ensemble-averaged momentum and scalar transport equations, respectively. The principal physical mechanisms governing the transport of the second-order concentration statistics of a passive scalar are modelled following Yee et al. (2009). The results of the simulation for the flow and concentration statistics are compared against two sets of high-quality water-channel measurement data obtained using laser induced fluorescence (for concentration) and laser Doppler anemometry (for velocity). Keywords: bluff body; concentration variance; dispersion; RANS; rough-wall boundary- layer; urban environment. Reference to this paper should be made as follows: Wang, B-C., Yee, E. and Lien, F-S. (2010) ‘Prediction of second-order concentration statistics for dispersing plumes in obstacle arrays’, Progress in Computational Fluid Dynamics, Vol. 10, No. 4, pp.252–262. Biographical notes: Bing-Chen Wang has been an Assistant Professor in the Department of Mechanical and Manufacturing Engineering at the University of Manitoba since 2008. After receiving his PhD Degree from the University of Saskatchewan in 2004, he was awarded a NSERC Visiting Fellowship to conduct postdoctoral research at Defence Research & Development Canada, in Suffield, Alberta. After completing his three-year postdoctoral program, he was appointed as a Defence Scientist with Defence R&D Canada – Suffield one year before he joined the University of Manitoba. His current research interests include large-eddy simulation, hybrid RANS/LES, environmental flow and dispersion, turbulence modelling, convective heat and mass transfer, and high-performance scientific computing. Eugene Yee has been a Defence Scientist at Defence R&D Canada – Suffield since 1987 and Adjunct Professor at the University of Waterloo and University of Manitoba since 2001 and 2008, respectively. He serves also as a Scientific Advisor and Consultant to many branches within the Department of National Defence and other federal government agencies (in both Canada and USA) on toxic gas and aerosol hazard assessment. He is currently the Canadian National Leader to The Technical Cooperation Program (TTCP), Chemical Biological and Radiological Defence Group, Technical Panel 9 on CBRN Model Copyright © 2010 Inderscience Enterprises Ltd.