Scattergraph Principles and Practice
PART 7 - Self-Cleansing in Existing Sewers
June 30, 2020 @ 12 Noon EDT, 11 AM CDT, 10 AM MDT, 9AM PDT
Presentation Duration: Estimated 1 hour
The purpose of Part 1 is to provide a basic understanding of scattergraphs, including the fundamentals on which they are built. An overview of uniform flow conditions is provided, as well as the Manning Equation that represents them. Insights that can be gained by viewing flow monitor data through the lens of the Manning Equation will also be discussed. Important things can be learned by noting when they agree and when they disagree. These fundamentals provide a basic understanding of scattergraphs and serve as building blocks to more advanced principles to follow in this webinar series.
The purpose of Part 5 is to discuss the practical application of the Froude Number to flow monitoring. Engineers are aware of the instability associated with critical flow conditions and are generally advised to avoid them during sewer design. However, such conditions are often encountered in existing sewers and can impact the reliability of flow monitor data.
The Froude number (Fr) is a dimensionless number used to describe flow conditions within a sewer. These conditions can be illustrated on a scattergraph using iso-Froude lines. Certain flow conditions such as hydraulic jumps, sewer bores, and undular jumps are readily identified by evaluating flow monitor data with respect to iso-Froude lines. Practical examples from flow monitor locations are provided, demonstrating the scattergraph signatures of various transcritical and near-critical phenomena. Flow monitors can operate well in sewers under subcritical and supercritical condition, but accuracy may deteriorate near the transition. Such conditions should be avoided when possible in flow monitoring applications.
Kevin Enfinger, P.E.
Kevin is a Product Manager at ADS Environmental Services with 25 years of experience in environmental engineering and consulting. He holds a Bachelor of Science in Chemical Engineering from the University of Florida and is a member of the American Society of Civil Engineers and the Water Environment Federation.
SPEAKER: Kevin Enfinger, P.E.
Important engineering decisions are made every day regarding sanitary sewer, combined sewer, and storm sewer systems and often require the use of rainfall data. See how selecting the right equipment in the right quantities for your local rainfall conditions and your specific applications will lead to a successful rainfall monitoring program.
SPEAKER: Jay Boyd
Optimize Cleaning – See how new technologies are helping municipalities reduce cleaning by up to 80%, safeguard against SSOs with 24/7 monitoring, and avoid harmful side-effects of overcleaning.