Newly Developed Vortex Drop Shaft Spillway

Significance 

Hydropower projects such as dams are generally susceptible to various technical challenges caused by complex geological conditions. Among the challenges, corrosion prevention and energy dissipation are the dominant ones. Unfortunately, the present design relies majorly on the dam flood discharge which makes it difficult to achieve the desired design requirements because the energy dissipation and flood discharge configuration are limited by on-site field conditions. To this note, other flood discharge facilities have been developed to overcome various challenges. A good example is an annular vortex weir spillway. However, the factors influencing the discharge coefficient at the inlet and the swirling intensity have not been fully explored.

A group of researchers at China Institute of Water Resources and Hydropower Research: Professor Zhi-Ping Liu, Professor Xin-Lei Guo, Professor Qing-Fu Xia, engineer Hui Fu, Professor Tao Wang, and Professor Xing-Lin Dong designed an internal energy dissipation shaft flood discharge tunnel with vortex flow. The shaft spillway comprised of an inlet structure that included an annular weir, swirling-flow-generating piers and a vertical as well as an outlet structure. Besides, the proper design was ensured by a discharge coefficient equation-based on the dimensionless weir head thus giving way for model experimental and numerical simulations. Their aim was to investigate the main factors influencing the discharge coefficient at the inlet including the pier weir angle, the number of piers, pier height and pier head. Furthermore, hydraulic characteristics such as the air core distribution, pressure profiles, flow patterns among others were determined and compared with the measured experimental data. The work is published in Journal of Hydraulic Engineering..

From the experimental results, the authors observed that the flow around the inlet was divided into two regions. This included submerged-flow region at the pers and free-flow swirling region found near the pier. In the submerged region, linear flow growth rate with the relative dimensionless weir head was noted with approximately constant discharge coefficient of about 0.223. This was attributed to the automatic regulation of the inflow angle to enhance discharge capacity under the inertial forces in the underwater swirl piers. This also explains the ability of the vertical flow shaft to maintain a flow state without inhaling water under the working flood discharge condition.

The research team successfully designed a vortex shaft drop tunnel with a new inlet which exhibited a high level of energy dissipation. Thus, the study provides the basis for understanding the flow characteristics of water and particularly the self-regulating under water swirl piers. It was necessary to investigate the hydraulic parameter characteristic of the designed inlet. The similarity in the computational results and the numerical simulation results both in values and patterns confirmed the practicality and effectiveness of the analysis. The numerical simulation model resulted in significant differences between the air entrainment attributed to whether or not the air compressibility as taken into consideration. This may have influenced the model predictions for the entrainment air in one way or the other.

Newly Developed Vortex Drop Shaft Spillway - Advances in Engineering

Newly Developed Vortex Drop Shaft Spillway - Advances in Engineering

Newly Developed Vortex Drop Shaft Spillway - Advances in Engineering

About the author

Zhiping Liu is a Professor of Engineering in China Institute of Water Resources and Hydropower Research (IWHR), Beijing, China. He received his MS degree from IWHR in 1986. He once studied and worked in Japan. He had been engaged in the work of water conservancy over a long period of time and had made significant contribution to the development of water resources in China. He won four Second Prize of State Science and Technology Progress Awards. His research interests include the engineering hydraulics and hydroinformatics.

About the author

Xinlei Guo is a Professor of Engineering in the State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research (IWHR), Beijing, China. He received his MS degrees from Wuhan University, and PhD degree from IWHR. His research interests include the engineering hydraulics, river ice dynamics and hydraulic control mechanisms.

He has authored over 70 journal papers and secured 40 national invention patents. He is the recipient of 2016 the Second Prize of State Science and Technology Progress Awards for his pioneering research on engineering hydraulics.

About the author

Qingfu Xia is a Professor of Engineering in the State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research (IWHR), Beijing, China. He received his MS degrees from Dalian University of Technology (DUT), and PhD degree from IWHR. His research interests include the engineering hydraulics and hydro informatics.

About the author

Hui Fu is a Senior Engineer in the State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research (IWHR), Beijing, China. He received his MS degrees from Hefei University of Technology.

His research interests include the engineering hydraulics and river ice dynamics. He has authored over 40 journal papers and secured 30 national invention patents.

About the author

Tao Wang is a Professor of Engineering in the State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research (IWHR), Beijing, China. She received her MS degrees in 2004 and PhD degree in 2011 from IWHR. Her research interests include the engineering hydraulics, river ice forecast and disaster prevention.

About the author

Xinglin Dong is a Distinguished Professor of Engineering in China Institute of Water Resources and Hydropower Research (IWHR), Beijing, China. He received his BS degree from Dalian University of Technology, Dalian, China in 1954. He  made significant contribution to the spillway hydraulics in China. His research interests include the hydraulic structure, flood discharge and energy dissipation.

Reference

Liu, Z., Guo, X., Xia, Q., Fu, H., Wang, T., & Dong, X. (2018). Experimental and Numerical Investigation of Flow in a Newly Developed Vortex Drop Shaft Spillway. Journal of Hydraulic Engineering, 144(5), 04018014.

Go To Journal of Hydraulic Engineering

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