American Society of Civil Engineers


Comparison of Piano Key and Rectangular Labyrinth Weir Hydraulics


by R. M. Anderson, (M.S. Research Assistant, Utah Water Research Laboratory, Dept. of Civil and Environmental Engineering, Utah State Univ., 8200 Old Main Hill, Logan, UT 84322-8200. E-mail: rickyanderson@gmail.com) and B. P. Tullis, (corresponding author), M.ASCE, (Associate Professor, Utah Water Research Laboratory, Dept. of Civil and Environmental Engineering, Utah State Univ., 8200 Old Main Hill, Logan, UT 84322-8200. E-mail: blake.tullis@usu.edu)

Journal of Hydraulic Engineering, Vol. 138, No. 4, April 2012, pp. 358-361, (doi:  http://dx.doi.org/10.1061/(ASCE)HY.1943-7900.0000509)

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Document type: Technical Note
Abstract: The piano key or PK weir represents a relatively new hydraulic structure in both research and practice. There is currently a limited understanding regarding the influence of the large number of PK weir geometric parameters on hydraulic performance. A specific PK weir design configuration, suggested to be highly efficient, has been presented in the literature. By using laboratory-scale physical models, the hydraulic efficiency of the recommended PK weir design was compared with that of a geometrically comparable rectangular labyrinth weir, with and without sloping floors (consistent with the PK weir geometry) installed in the inlet and outlet keys or cycles. In general, the test data showed that the PK weir was more efficient than the geometrically comparable rectangular labyrinth weir, a fact likely attributable to a reduction in entrance losses associated with the PK weir inlet key geometry.


ASCE Subject Headings:
Weirs
Hydraulics
Hydraulic structures

Author Keywords:
Piano key weir
Rectangular labyrinth weir
Weir discharge efficiency