Start Date

2018 4:20 PM

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Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Abstract

Since the first Piano Key Weir (PKW) was built at Goulours Dam in France in 2006 by Electricité de France their importance as flood release structure for gravity dams or as implementation in river systems increased significantly. PKWs are a result of a consequent development of labyrinth weirs. In 1998 first studies with preliminary geometries were performed in France and improved by Blanc and Lempérière (2001). Due to the nonlinear shape, the PKW’s efficiency is – compared to linear weirs – majorly increased, since the effective overflow length will be increased. In the past, a lot of research in terms of physical modeling, computational fluid dynamics (CFD) studies or research in prototype scale were carried out. Numerical investigations can provide important knowledge of flow parameters and provide a cost-effective tool to investigate numerous PKW designs. Although a lot of numerical PKW simulation were carried out, additional in-depth research is still needed. For numerical simulations, the mesh dependence is a major criterion with a large influence on the result quality in respect to e.g. water surface levels or flow velocities. The present paper deals with the mesh dependence related to PKW discharge coefficients. It will provide recommendations for numerical PKW simulations by investigating sufficient maximum mesh sizes with the Grind Convergence Method (GCI).

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May 17th, 4:20 PM

Numerical Uncertainty of Piano Key Weir Discharge Coefficient Estimations by Means of 3D CFD Modelling - a Preliminary Study

Since the first Piano Key Weir (PKW) was built at Goulours Dam in France in 2006 by Electricité de France their importance as flood release structure for gravity dams or as implementation in river systems increased significantly. PKWs are a result of a consequent development of labyrinth weirs. In 1998 first studies with preliminary geometries were performed in France and improved by Blanc and Lempérière (2001). Due to the nonlinear shape, the PKW’s efficiency is – compared to linear weirs – majorly increased, since the effective overflow length will be increased. In the past, a lot of research in terms of physical modeling, computational fluid dynamics (CFD) studies or research in prototype scale were carried out. Numerical investigations can provide important knowledge of flow parameters and provide a cost-effective tool to investigate numerous PKW designs. Although a lot of numerical PKW simulation were carried out, additional in-depth research is still needed. For numerical simulations, the mesh dependence is a major criterion with a large influence on the result quality in respect to e.g. water surface levels or flow velocities. The present paper deals with the mesh dependence related to PKW discharge coefficients. It will provide recommendations for numerical PKW simulations by investigating sufficient maximum mesh sizes with the Grind Convergence Method (GCI).