Location

Virtual

Start Date

7-5-2021 12:00 AM

End Date

7-8-2021 12:00 AM

Description

This paper presents a study of a tridimensional low-head hydraulic jump stilling basin by using both physical and numerical models. Laboratory tests up to 15 hours in duration were carried out in a 1.9 m wide and 14 m long flume. Four gates produced a jet with a submerged hydraulic jump in a positive-step stilling basin, after which scour developed in a nearly uniform sand bed. Acoustic Doppler Velocimeter, piezometers and image processing were used to collect the hydrodynamic data, and Reynolds Averaged Navier-Stokes simulations developed in OpenFOAM were tested for validation purposes. Then, the study focused on (1) the temporal evolution of the experimental scour depth downstream the stilling basin and (2) the efficiency of the numerical models to reproduce the interior fields. Regarding the first point, it was found that temporal scour evolution agrees with empirical dimensionless formulation, but differences in magnitude were found, indicating that some variables should be further investigated. The validation of numerical models has shown that the K-Epsilon Standard model is much better than the K-Omega SST counterpart in reproducing velocity fields but similar values were found for turbulent kinetic energy. Pressure fluctuations numerical coefficient also showed values similar to those found by other authors, however lateral flow and Reynolds stress issues appeared because of the tridimensional nature of the case study.

Share

COinS
 
Jul 5th, 12:00 AM Jul 8th, 12:00 AM

Experimental and Numerical Analysis of the Hydraulic Jump Stilling Basin and the Downstream Scour Depth

Virtual

This paper presents a study of a tridimensional low-head hydraulic jump stilling basin by using both physical and numerical models. Laboratory tests up to 15 hours in duration were carried out in a 1.9 m wide and 14 m long flume. Four gates produced a jet with a submerged hydraulic jump in a positive-step stilling basin, after which scour developed in a nearly uniform sand bed. Acoustic Doppler Velocimeter, piezometers and image processing were used to collect the hydrodynamic data, and Reynolds Averaged Navier-Stokes simulations developed in OpenFOAM were tested for validation purposes. Then, the study focused on (1) the temporal evolution of the experimental scour depth downstream the stilling basin and (2) the efficiency of the numerical models to reproduce the interior fields. Regarding the first point, it was found that temporal scour evolution agrees with empirical dimensionless formulation, but differences in magnitude were found, indicating that some variables should be further investigated. The validation of numerical models has shown that the K-Epsilon Standard model is much better than the K-Omega SST counterpart in reproducing velocity fields but similar values were found for turbulent kinetic energy. Pressure fluctuations numerical coefficient also showed values similar to those found by other authors, however lateral flow and Reynolds stress issues appeared because of the tridimensional nature of the case study.

 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.