Probabilistic ocean outfall design

Thesis (M.Eng.)--Memorial University of Newfoundland, 1998. Engineering and Applied Science Bibliography: leaves 166-173 Factors affecting initial dilution and bacterial concentration at an area near the outfall discharge, e.g. sewage flow rate, seawater currents and bacterial decay, are highly vari...

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Main Author: Mukhtasor, 1969-
Other Authors: Memorial University of Newfoundland. Faculty of Engineering and Applied Science
Format: Thesis
Language:English
Published: 1998
Subjects:
Online Access:http://collections.mun.ca/cdm/ref/collection/theses3/id/197547
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spelling ftmemorialunivdc:oai:collections.mun.ca:theses3/197547 2023-05-15T17:23:28+02:00 Probabilistic ocean outfall design Mukhtasor, 1969- Memorial University of Newfoundland. Faculty of Engineering and Applied Science 1998 xiv, 185 leaves : ill. Image/jpeg; Application/pdf http://collections.mun.ca/cdm/ref/collection/theses3/id/197547 eng eng Electronic Theses and Dissertations (26.14 MB) -- http://collections.mun.ca/PDFs/theses/Mukhtasor_BradleyJ_masters.pdf a1265351 http://collections.mun.ca/cdm/ref/collection/theses3/id/197547 The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries Ocean outfalls--Design Text Electronic thesis or dissertation 1998 ftmemorialunivdc 2017-01-22T00:09:16Z Thesis (M.Eng.)--Memorial University of Newfoundland, 1998. Engineering and Applied Science Bibliography: leaves 166-173 Factors affecting initial dilution and bacterial concentration at an area near the outfall discharge, e.g. sewage flow rate, seawater currents and bacterial decay, are highly variable. Because of this, a probabilistic approach for ocean outfall design and analysis is essential in predicting the performance of the outfall and in reflecting the probabilistic nature of the initial dilution and bacterial concentration. -- The intention of this thesis is to develop and apply a design procedure using a probabilistic method to calculate initial dilution and bacterial concentration at a location of interest. The scope of the study is directed at design and analysis for a horizontal buoyant round jet in a density unstratified seawater environment. Uncertainty of five parameters of design, i.e. sewage flow rate, tidal height, seawater currents, decay parameter, and bacterial concentration in the sewage before discharge into seawater are taken into account in this study. -- A comparison of the probabilistic approach with the deterministic approach shows that the probabilistic approach may provide a full range of possible values of the parameters of interest other than a fixed value. Associated probability values for the parameters of interest can also be obtained using the probabilistic methods. The procedure for outfall design using a probabilistic approach is straight forward, and may work in practice because the analysis of an existing outfall (the Spaniard's Bay Outfall, Newfoundland, Canada) has resulted in good agreement with field data. -- Comparison among the various probabilistic methods studied shows that all methods generally give the same answers for the case of initial dilution, except for a small probability of failure which is typically less 4 %. It is found that First Order Second Moment ( FOSM), Improved Mean-First Order Second Moment (IM-FOSM) and Advanced First Order Second Moment (AFOSM) with assumed normal parameters work well for use in analysis of initial dilution. In practice, the use of FOSM is recommended for its simplicity. -- For the case of bacterial concentration, FOSM gives poor results because the performance function in this case is complex and non linear, but AFOSM with assumed non-normal parameters is recommended. Monte Carlo Simulations (MCS) may also be used if a fast computer and software are available. It should be remembered that the choice of the probability method should consider the problem under investigation as well as the cost and facilities available. Thesis Newfoundland studies University of Newfoundland Memorial University of Newfoundland: Digital Archives Initiative (DAI) Canada
institution Open Polar
collection Memorial University of Newfoundland: Digital Archives Initiative (DAI)
op_collection_id ftmemorialunivdc
language English
topic Ocean outfalls--Design
spellingShingle Ocean outfalls--Design
Mukhtasor, 1969-
Probabilistic ocean outfall design
topic_facet Ocean outfalls--Design
description Thesis (M.Eng.)--Memorial University of Newfoundland, 1998. Engineering and Applied Science Bibliography: leaves 166-173 Factors affecting initial dilution and bacterial concentration at an area near the outfall discharge, e.g. sewage flow rate, seawater currents and bacterial decay, are highly variable. Because of this, a probabilistic approach for ocean outfall design and analysis is essential in predicting the performance of the outfall and in reflecting the probabilistic nature of the initial dilution and bacterial concentration. -- The intention of this thesis is to develop and apply a design procedure using a probabilistic method to calculate initial dilution and bacterial concentration at a location of interest. The scope of the study is directed at design and analysis for a horizontal buoyant round jet in a density unstratified seawater environment. Uncertainty of five parameters of design, i.e. sewage flow rate, tidal height, seawater currents, decay parameter, and bacterial concentration in the sewage before discharge into seawater are taken into account in this study. -- A comparison of the probabilistic approach with the deterministic approach shows that the probabilistic approach may provide a full range of possible values of the parameters of interest other than a fixed value. Associated probability values for the parameters of interest can also be obtained using the probabilistic methods. The procedure for outfall design using a probabilistic approach is straight forward, and may work in practice because the analysis of an existing outfall (the Spaniard's Bay Outfall, Newfoundland, Canada) has resulted in good agreement with field data. -- Comparison among the various probabilistic methods studied shows that all methods generally give the same answers for the case of initial dilution, except for a small probability of failure which is typically less 4 %. It is found that First Order Second Moment ( FOSM), Improved Mean-First Order Second Moment (IM-FOSM) and Advanced First Order Second Moment (AFOSM) with assumed normal parameters work well for use in analysis of initial dilution. In practice, the use of FOSM is recommended for its simplicity. -- For the case of bacterial concentration, FOSM gives poor results because the performance function in this case is complex and non linear, but AFOSM with assumed non-normal parameters is recommended. Monte Carlo Simulations (MCS) may also be used if a fast computer and software are available. It should be remembered that the choice of the probability method should consider the problem under investigation as well as the cost and facilities available.
author2 Memorial University of Newfoundland. Faculty of Engineering and Applied Science
format Thesis
author Mukhtasor, 1969-
author_facet Mukhtasor, 1969-
author_sort Mukhtasor, 1969-
title Probabilistic ocean outfall design
title_short Probabilistic ocean outfall design
title_full Probabilistic ocean outfall design
title_fullStr Probabilistic ocean outfall design
title_full_unstemmed Probabilistic ocean outfall design
title_sort probabilistic ocean outfall design
publishDate 1998
url http://collections.mun.ca/cdm/ref/collection/theses3/id/197547
geographic Canada
geographic_facet Canada
genre Newfoundland studies
University of Newfoundland
genre_facet Newfoundland studies
University of Newfoundland
op_source Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries
op_relation Electronic Theses and Dissertations
(26.14 MB) -- http://collections.mun.ca/PDFs/theses/Mukhtasor_BradleyJ_masters.pdf
a1265351
http://collections.mun.ca/cdm/ref/collection/theses3/id/197547
op_rights The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission.
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