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Coanda-Effect Screen Research

Tony L. Wahl
Hydraulic Engineer
U.S. Department of the Interior
Bureau of Reclamation

Schematic diagram
Schematic diagram
(click for larger image)


Screen under test photo
Screen under test
(click for larger image)

Software

  • Coanda-Effect Screen Analysis Software - A Windows-based program for analysis and design of Coanda-effect screens.  Version 0.5 was posted on June 9, 2011. This program is a 32-bit application for Windows 95 and later systems. This version provides output of the thru-slot velocity and the ratio of sweeping to thru-slot velocity along the length of the screen.

Publications

  • Design Guidance for Coanda-Effect Screens (2003) - Reclamation Research Report R-03-03.  This report applies the Coanda computer program to develop design guidance recommendations for a variety of screen configurations.  Case studies of actual screen installations are provided.
  • Hydraulic Performance of Coanda-Effect Screens (2001) - This paper presents the complete numerical model for determining the discharge through a Coanda-effect screen structure. For a given inflow rate, the model computes the flow profile along the length of the screen and the total discharge through the screen as a function of the structure dimensions (e.g., drop height, screen length, screen arc radius, etc.) and the screen material properties. The paper also presents a refined model for predicting the discharge characteristics of tilted-wire screen materials as a function of the tilt angle, wire size, slot size, and the Froude number, Reynolds number and Weber number of the flow over the screen.
  • Laboratory Testing and Numerical Modeling of Coanda-Effect Screens (2000) - This paper describes the mechanics of flow over and through Coanda-effect screens and presents a numerical model for predicting screen performance. The paper also presents a model for evaluating the discharge coefficients of tilted-wire screens and shows that the discharge coefficient is a unique function of the Froude number and the screen geometry.
  • Hydraulic Testing of Static Self-Cleaning Inclined Screens (1995) - This paper reports results of the first series of laboratory tests conducted by Reclamation.

Links: Some Commercial Sources for Coanda-Effect Screens

Tony Wahl's Reclamation Home Page

Last reviewed: 05/08/13