Complete Characterization of Turbulence in Directions, Wind Speeds, - PowerPoint PPT Presentation

Complete Characterization of Turbulence in an Urban Canyon Under All Wind Complete Characterization of Turbulence in Directions, Wind Speeds, and an Urban Canyon Under All Wind Thermal Stability Conditions Directions, Wind Speeds, and Thermal Amir A. Aliabadi, Mohsen Moradi, Denis Clement, Stability Conditions William D. Lubitz, & Bahram Gharabaghi Introduction Amir A. Aliabadi, Mohsen Moradi, Denis Clement, Background William D. Lubitz, & Bahram Gharabaghi Objective Methodology Experimental University of Guelph Results and American Meteorological Society, 10th International Conference on Urban Discussion Climate/ 14th Symposium on the Urban Environment Mean Quantities Turbulence Statistics Scaling Analysis Conclusions August 1, 2018 Future Work Acknowledgements References 1 / 27

Complete Outline Characterization of Turbulence in an Urban Canyon Introduction Under All Wind Directions, Wind Background Speeds, and Thermal Stability Objective Conditions Amir A. Aliabadi, Methodology Mohsen Moradi, Denis Clement, Experimental William D. Lubitz, & Bahram Gharabaghi Results and Discussion Mean Quantities Introduction Background Turbulence Statistics Objective Scaling Analysis Methodology Experimental Results and Conclusions Discussion Mean Quantities Future Work Turbulence Statistics Scaling Analysis Conclusions Acknowledgements Future Work References Acknowledgements References 2 / 27

Complete Introduction Characterization of Turbulence in an Background Urban Canyon Under All Wind Directions, Wind Speeds, and Thermal Stability Conditions Amir A. Aliabadi, ◮ Urban roughness sublayer: the lowest portion of the Mohsen Moradi, Denis Clement, atmospheric boundary layer over urban areas that William D. Lubitz, & Bahram exhibits numerous complexities [Raupach et al., 1980] Gharabaghi ◮ Urban micro-climate and air quality: driven by vertical Introduction and horizontal exchanges of momentum, heat, and Background Objective pollutants within the urban roughness sublayer Methodology ◮ Gaps in the literature: few field observations, oblique Experimental Results and wind directions, low wind speeds, non-neutral stability Discussion Mean Quantities conditions, horizontal exchanges, scaling Turbulence Statistics Scaling Analysis Conclusions Future Work Acknowledgements References 3 / 27

Complete Introduction Characterization of Turbulence in an Objective Urban Canyon Under All Wind Directions, Wind Speeds, and Thermal Stability Conditions Amir A. Aliabadi, Mohsen Moradi, Denis Clement, William D. Lubitz, & Bahram Gharabaghi Introduction Background Objective Methodology Experimental Results and Discussion Mean Quantities Turbulence Statistics Scaling Analysis Figure: Reek Walk at University of Guelph; Quasi 2D canyon, 55-m Conclusions long and 13-m high with unit aspect ratio [Aliabadi et al., 2018] Future Work Acknowledgements References 4 / 27

Complete Introduction Characterization of Turbulence in an Objective Urban Canyon Under All Wind Directions, Wind Speeds, and Thermal Stability Conditions Amir A. Aliabadi, Mohsen Moradi, Denis Clement, William D. Lubitz, & Bahram Gharabaghi Introduction Background Objective Methodology Experimental Results and Discussion Mean Quantities Turbulence Statistics Figure: Turfgrass Institute rural site; 1 . 2 km away from campus; Scaling Analysis Weather station for World Meteorological Organization (WMO) Conclusions operated by Environment and Climate Change Canada (ECCC) Future Work [Aliabadi et al., 2018] Acknowledgements References 5 / 27

Complete Introduction Characterization of Turbulence in an Objective Urban Canyon Under All Wind Directions, Wind Speeds, and Thermal Stability Conditions Amir A. Aliabadi, Mohsen Moradi, ◮ Investigate Urban Heat Island (UHI) effect. Denis Clement, William D. Lubitz, ◮ Quantify horizontal and vertical turbulence exchanges & Bahram Gharabaghi of momentum and heat. Introduction ◮ Consider a comprehensive set of wind directions, wind Background Objective speeds, and thermal stability conditions. Methodology ◮ Perform scaling analysis with surface and near surface Experimental Results and parameters. Discussion Mean Quantities Turbulence Statistics Scaling Analysis Conclusions Future Work Acknowledgements References 6 / 27

Complete Methodology Characterization of Turbulence in an Experimental Urban Canyon Under All Wind Directions, Wind Speeds, and Thermal Stability Conditions ◮ Ultrasonic anemometers: 2 Young 81000 anemometers Amir A. Aliabadi, 2-m high above street and roof; sampling at 4 Hz Mohsen Moradi, Denis Clement, William D. Lubitz, ◮ Temperature and relative humidity: 1 Campbell & Bahram Gharabaghi Scientific HMP60 at street level ◮ Data logging: 2 Campbell Scientific CR-1000 data Introduction Background loggers Objective Methodology ◮ Thermal imaging: 1 FLIR E4 thermal camera for Experimental surface temperature mapping Results and Discussion ◮ Tethered balloon: Tethered And Navigated Air Blimp Mean Quantities Turbulence Statistics Scaling Analysis (TANAB) to measure relative humidity and temperature Conclusions Future Work Acknowledgements References 7 / 27

Complete Methodology Characterization of Turbulence in an Experimental Urban Canyon Under All Wind Directions, Wind Speeds, and Thermal Stability Conditions Amir A. Aliabadi, Mohsen Moradi, Denis Clement, William D. Lubitz, & Bahram Gharabaghi Introduction Background Objective Methodology Experimental Results and Discussion Figure: Left: TANAB0, 2-m 3 Latex balloon, filled with helium, Mean Quantities Turbulence Statistics 1.2-kg lift, measures position, temperature, and relative humidity; Scaling Analysis Right TANAB1, 8-m 3 Polyurethane balloon filled with helium, Conclusions 3.0-kg lift, measures position, temperature, relative humidity, Future Work pressure, wind, and thermal imaging Acknowledgements References 8 / 27

Complete Results and Discussion Characterization of Turbulence in an Mean Quantities Urban Canyon Under All Wind Directions, Wind Speeds, and Thermal Stability Conditions Amir A. Aliabadi, Mohsen Moradi, Denis Clement, William D. Lubitz, & Bahram Gharabaghi Introduction Background Objective Methodology Experimental Results and Discussion Mean Quantities Turbulence Statistics Scaling Analysis Conclusions Figure: Top: atmospheric and surface temperatures; Bottom: Future Work Urban Heat Island (UHI) intensity measured as 0 . 7 K ± 1 . 2 K; Acknowledgements compared to 1.5-4.0K for London, UK, in September References [Barlow et al., 2015] 9 / 27

Complete Results and Discussion Characterization of Turbulence in an Mean Quantities Urban Canyon Under All Wind Directions, Wind Speeds, and Thermal Stability Conditions Amir A. Aliabadi, Mohsen Moradi, Denis Clement, William D. Lubitz, & Bahram Gharabaghi Introduction Background Objective Methodology Experimental Results and Discussion Mean Quantities Turbulence Statistics Scaling Analysis Figure: Left: TANAB profiles of temperature; Conclusions stable-neutral-unstable roughness sublayer; local heating near roof Future Work at 0700 Local Standard Time (LST); Right: TANAB profiles of Acknowledgements relative humidity; local heating near roof and reduction in relative References humidity at 0700 LST 10 / 27

Complete Results and Discussion Characterization of Turbulence in an Turbulence Statistics Urban Canyon Under All Wind Directions, Wind Speeds, and Thermal Stability Conditions Amir A. Aliabadi, Mohsen Moradi, Denis Clement, William D. Lubitz, & Bahram Gharabaghi Introduction Background Objective Methodology Experimental Results and Discussion Mean Quantities Turbulence Statistics Scaling Analysis Figure: Turbulence exchanges can be defined in three directions: Conclusions vertical, cross canyon, and along canyon [Aliabadi et al., 2018] Future Work Acknowledgements References 11 / 27

Complete Results and Discussion Characterization of Turbulence in an Turbulence Statistics Urban Canyon Under All Wind Directions, Wind Speeds, and Thermal Stability Roof Street Conditions Amir A. Aliabadi, Mohsen Moradi, Denis Clement, William D. Lubitz, & Bahram Gharabaghi Introduction Background Objective Methodology Experimental Results and Discussion Mean Quantities Turbulence Statistics Scaling Analysis Conclusions Figure: Hourly variance of temperature t 2 (a, b), and turbulence Future Work kinetic energy (TKE) k (c, d), classified based on the roof wind Acknowledgements 2 + V 2 ) 1 / 2 H angle and the building Reynolds number Re H = ( U = S H References ν ν 12 / 27

Complete Results and Discussion Characterization of Turbulence in an Turbulence Statistics Urban Canyon Under All Wind Directions, Wind Speeds, and Thermal Stability Roof Street Conditions Amir A. Aliabadi, Mohsen Moradi, Denis Clement, William D. Lubitz, & Bahram Gharabaghi Introduction Background Objective Methodology Experimental Results and Discussion Mean Quantities Turbulence Statistics Scaling Analysis Conclusions Figure: Hourly horizontal turbulent heat fluxes ut (a, b) and vt (c, Future Work d), classified based on the roof wind angle and the building Acknowledgements Reynolds number Re H References 13 / 27