Flow Dynamics in Combined Storm‐Sewer Systems: Application of the Illinois Transient Model (ITM) to the Calumet TARP System in Chicago, Illinois

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Conference Proceeding

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The large variations in the inflows together with the complex operation of Combined Sewer Overflow (CSO) systems may result in flow conditions that vary from dry to free surface flow to partly free surface-partly pressurized flow (mixed flow), to fully pressurized flow. Transitions from one flow regime to another are governed by flow instabilities (Yen 1986). Some of these instabilities may produce undesirable events such as geysering phenomena, blow-off of manhole covers, manhole overtopping or structural damage of the system. In order to asses the impact of these undesirable events a transient analysis of these systems for various scenarios becomes important.