Final Report: Prediction and quantification of Combined Sewer Outflows under extreme storm events: Flow dynamics and Reduction of Combined Sewer Outflows

EPA Grant Number: R835187
Title: Prediction and quantification of Combined Sewer Outflows under extreme storm events: Flow dynamics and Reduction of Combined Sewer Outflows
Investigators: Leon, Arturo
Institution: Oregon State University
EPA Project Officer: Hiscock, Michael
Project Period: June 1, 2012 through May 31, 2017
Project Amount: $265,528
RFA: Extreme Event Impacts on Air Quality and Water Quality with a Changing Global Climate (2011) RFA Text |  Recipients Lists
Research Category: Global Climate Change , Earth Sciences - Environmental Science , Aquatic Ecology and Ecosystems , Aquatic Ecosystems , Air Quality and Air Toxics , Water Quality , Climate Change , Air , Water

Objective:

The overall goal of the proposed research is to get insights on the mechanisms leading to geysering in vertical shafts and provide insights into retrofitting strategies to minimize geysers in stormwater and combined sewer systems. The specific objectives of the project have been refined during the course of the project. The original objectives proposed for this project are: (1) To develop a mathematical formulation for common cases of overflow discharges (e.g., CSOs) at vertical shafts and near-horizontal outlets under extreme flow events; (2) To implement the mathematical formulation of overflows into a state-of-the-art open source (free and open access) transient flow model that can be used in complex CSSs; (3) To validate the overflow discharge framework under highly dynamic flow conditions.

The refined objectives are to: (1) produce violent geysers in an experimental setting; (2) numerically reproduce violent geysers; (3) provide insights into retrofitting strategies to minimize geysers in stormwater and combined sewer systems.

Summary/Accomplishments (Outputs/Outcomes):

We have performed over 500 geyser laboratory experiments and over over fifty 3D CFD numerical simulations of air-water geyser flows.  The key findings are: (1) geysers resembling the characteristics (e.g., few consecutive eruptions within a total time frame of a couple of seconds) of those occurred in actual stormwater and combined sewer systems are produced in a laboratory setting for the first time; (2) the experimental study resulted in a dimensionless relationship to predict eruption height and velocity in vertical shafts as a function of dimensionless air mass flow rate; (3) The geyser intensity (e.g., height) was found to increase with the dropshaft height and the air mass flow rate; (4) the laboratory geysers were reproduced using a three-dimensional numerical model; (5) suggestions on potential retrofitting strategies for minimizing geysers are provided.


Journal Articles on this Report : 4 Displayed | Download in RIS Format

Other project views: All 17 publications 4 publications in selected types All 4 journal articles
Type Citation Project Document Sources
Journal Article Leon AS. Mathematical models for quantifying eruption velocity in degassing pipes based on exsolution of a single gas and simultaneous exsolution of multiple gases. Journal of Volcanology and Geothermal Research 2016;323:72-79. R835187 (2015)
R835187 (Final)
  • Abstract: ScienceDirect-Abstract
    Exit
  • Other: Harvard-Abstract
    Exit
  • Journal Article Chegini, T., Phan, M. K. and Leon, A. S. (2017). Three-dimensional numerical modeling of violent geysers in vertical shafts. Journal of Hydraulic Research. Under review. R835187 (Final)
    not available
    Journal Article Leon, A. S. (2017). Mechanisms that lead to violent geysers in vertical shafts. Journal of Hydraulic Research. Under review. Accepted with minor revisions. R835187 (Final)
    not available
    Journal Article Leon, A. S. (2017), Elayeb I. S., Tang, Y. (2017). An experimental study on violent geysers in vertical shafts. Journal of Hydraulic Research. Under review. R835187 (Final)
    not available

    Relevant Websites:

    Our violent geyser project

    VIOLENT GEYSERS IN STORMWATER AND COMBINED SEWER SYSTEMS Exit

     

    Illinois Transient Model (ITM)

    Illinois Transient Model (ITM) Exit

    Progress and Final Reports:

    Original Abstract
  • 2012 Progress Report
  • 2013 Progress Report
  • 2014 Progress Report
  • 2015 Progress Report