Tools to Support Design of Coanda-Effect Screens for Debris Exclusion and Fish Protection
This project will address two related research questions:
1) Can the flow capacity and associated profiles of flow conditions (depth, velocity, etc.) over Coanda-effect screen structures be predicted analytically for the range of screen slopes, flow conditions, and screen materials encountered in typical applications?
2) Can analytical methods for screen capacity estimation be documented and disseminated via journal articles and a user-friendly computer program that will assist screen designers?
Need and Benefit
¿Reclamation has multiple potential applications for Coanda-effect screen structures, including conversions of flood-
irrigation to sprinkler irrigation, conversions of open canals to pressurized pipelines, dewatering facilities, solids
separation, fish protection and fish handling applications, etc.
¿Previous research by Reclamation (Wahl 2001) advanced the state of the art significantly, but did not address a wide
enough range of flow conditions. The numerical model developed from the latest testing improves the accuracy of
flow measurement predictions from about ±50% to better than ±10%.
¿The new research publications and computer program will reduce designer's time needs dramatically (at least a
factor of 10) compared to performing manual calculations.
¿Without these research results, screen capacities could be poorly estimated, since previous studies considered a
narrow range of hydraulic conditions.
Contact the Principal Investigator for information about partners.
Bureau of Reclamation Review
The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.
Tools to Support Design of Coanda-Effect Screens for Debris Exclusion and Fish Protection (final, PDF, 5.1MB)
By Tony Wahl
Report completed on September 30, 2020