Unsteady wind effects on natural ventilation

Ventilation stacks are becoming increasingly common in the design of naturally ventilated buildings. The overall aim of the work described is ultimately to improve design procedures for such buildings. This thesis presents the experimental and theoretical investigation of unsteady wind effects on n...

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Main Author: Wang, Bo
Format: Thesis (University of Nottingham only)
Language:English
Published: 2010
Subjects:
Online Access:https://eprints.nottingham.ac.uk/11653/
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author Wang, Bo
author_facet Wang, Bo
author_sort Wang, Bo
building Nottingham Research Data Repository
collection Online Access
description Ventilation stacks are becoming increasingly common in the design of naturally ventilated buildings. The overall aim of the work described is ultimately to improve design procedures for such buildings. This thesis presents the experimental and theoretical investigation of unsteady wind effects on natural ventilation of a single envelope with multiple openings for both wind alone, and wind and buoyancy combined cases. There are two types of openings: namely the sharp-edged orifice and the long opening (stacks being treated as long openings). Two methods are adopted: 1) direct wind tunnel measurements using the hot-wire technique; 2) theoretical analysis using steady and unsteady envelope flow models. For the wind alone experiments, the influences of wind speed, wind direction and opening configuration on flow patterns are studied. For the wind and buoyancy combined tests, the transitional process between wind dominated and buoyancy dominated states are investigated. The direct velocity measurements provide the criteria for testing the validity of the theoretical models, and ways to improve them. Additionally, improvements are made to the experimental techniques: e.g. a precise unsteady calibration method of the hot-wire is developed; improvements of pressure measurements are also investigated. The experimental technique works well with multiple stacks. Even though small openings are used, some dependence of the mean pressure coefficient on opening configuration is observed. The theoretical models also work reasonably well with multiple stacks, yet it is observed that the accuracy of the theoretical models decrease with the increasing number of openings, and is sensitive to the chosen discharge coefficient which defines the characteristics of ventilation openings.
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format Thesis (University of Nottingham only)
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language English
last_indexed 2025-11-14T18:26:44Z
publishDate 2010
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spelling nottingham-116532025-02-28T11:14:48Z https://eprints.nottingham.ac.uk/11653/ Unsteady wind effects on natural ventilation Wang, Bo Ventilation stacks are becoming increasingly common in the design of naturally ventilated buildings. The overall aim of the work described is ultimately to improve design procedures for such buildings. This thesis presents the experimental and theoretical investigation of unsteady wind effects on natural ventilation of a single envelope with multiple openings for both wind alone, and wind and buoyancy combined cases. There are two types of openings: namely the sharp-edged orifice and the long opening (stacks being treated as long openings). Two methods are adopted: 1) direct wind tunnel measurements using the hot-wire technique; 2) theoretical analysis using steady and unsteady envelope flow models. For the wind alone experiments, the influences of wind speed, wind direction and opening configuration on flow patterns are studied. For the wind and buoyancy combined tests, the transitional process between wind dominated and buoyancy dominated states are investigated. The direct velocity measurements provide the criteria for testing the validity of the theoretical models, and ways to improve them. Additionally, improvements are made to the experimental techniques: e.g. a precise unsteady calibration method of the hot-wire is developed; improvements of pressure measurements are also investigated. The experimental technique works well with multiple stacks. Even though small openings are used, some dependence of the mean pressure coefficient on opening configuration is observed. The theoretical models also work reasonably well with multiple stacks, yet it is observed that the accuracy of the theoretical models decrease with the increasing number of openings, and is sensitive to the chosen discharge coefficient which defines the characteristics of ventilation openings. 2010-12-09 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/11653/1/Unsteady_wind_effects_on_natural_ventilation.pdf Wang, Bo (2010) Unsteady wind effects on natural ventilation. PhD thesis, University of Nottingham. ventilation natural ventilation ventilation stacks wind
spellingShingle ventilation
natural ventilation
ventilation stacks
wind
Wang, Bo
Unsteady wind effects on natural ventilation
title Unsteady wind effects on natural ventilation
title_full Unsteady wind effects on natural ventilation
title_fullStr Unsteady wind effects on natural ventilation
title_full_unstemmed Unsteady wind effects on natural ventilation
title_short Unsteady wind effects on natural ventilation
title_sort unsteady wind effects on natural ventilation
topic ventilation
natural ventilation
ventilation stacks
wind
url https://eprints.nottingham.ac.uk/11653/