Predicting velocities and turbulent exchange in isolated street canyons and at a neighborhood scale

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.

Bibliographic Details
Main Author: Hall, Terianne C
Other Authors: Leslie K. Norford.
Format: Thesis
Language:eng
Published: Massachusetts Institute of Technology 2011
Subjects:
Online Access:http://hdl.handle.net/1721.1/61867
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author Hall, Terianne C
author2 Leslie K. Norford.
author_facet Leslie K. Norford.
Hall, Terianne C
author_sort Hall, Terianne C
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description Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.
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spelling mit-1721.1/618672019-04-11T07:00:37Z Predicting velocities and turbulent exchange in isolated street canyons and at a neighborhood scale study of fluid dynamics at the neighborhood scale Hall, Terianne C Leslie K. Norford. Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Mechanical Engineering. Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010. Cataloged from PDF version of thesis. Includes bibliographical references (p. 127-130). Urban planners need a fast, simple model to assess the impact of early design phase iterations of neighborhood layout on the microclimate. Specifically, this model should be able to predict the expected urban heat island intensity and the locations in neighborhood layouts that are prone to pollutant retention. Current models are inadequate for this purpose because they use computationally intensive techniques to solve for flow through a neighborhood and often require a strong technical background for effective use of the models. In this thesis, we use analytical equations and empirical relationships to calculate the expected wind speeds in isolated, idealized street canyons. We demonstrate that flow in street canyons is driven by momentum exchange with the air above. We discuss the importance of flow separation and turbulent exchange between the urban canopy layer and the urban boundary layer for removing heat and pollutants from street canyons. Next, we introduce a method to parameterize this exchange and extend this work to more realistic street canyons and idealized neighborhoods. We evaluate this work using computational fluid dynamics and comparison to experimental results and models from the literature. We examine cases where the flow is influenced by buoyancy effects and assess the applicability of our work in these situations. Finally, we address how this work could be further developed into generalized planning guidelines and incorporated into a comprehensive model for urban planners. by Terianne Catherine Hall. S.M. 2011-03-24T20:18:53Z 2011-03-24T20:18:53Z 2010 2010 Thesis http://hdl.handle.net/1721.1/61867 705934657 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 130 p. application/pdf Massachusetts Institute of Technology
spellingShingle Mechanical Engineering.
Hall, Terianne C
Predicting velocities and turbulent exchange in isolated street canyons and at a neighborhood scale
title Predicting velocities and turbulent exchange in isolated street canyons and at a neighborhood scale
title_full Predicting velocities and turbulent exchange in isolated street canyons and at a neighborhood scale
title_fullStr Predicting velocities and turbulent exchange in isolated street canyons and at a neighborhood scale
title_full_unstemmed Predicting velocities and turbulent exchange in isolated street canyons and at a neighborhood scale
title_short Predicting velocities and turbulent exchange in isolated street canyons and at a neighborhood scale
title_sort predicting velocities and turbulent exchange in isolated street canyons and at a neighborhood scale
topic Mechanical Engineering.
url http://hdl.handle.net/1721.1/61867
work_keys_str_mv AT hallteriannec predictingvelocitiesandturbulentexchangeinisolatedstreetcanyonsandataneighborhoodscale
AT hallteriannec studyoffluiddynamicsattheneighborhoodscale