A Comprehensive approach using CFD and GIS for dam break risk analysis: A case study on Nagarjuna Sagar earthen dam

Abstract

This study presents a comprehensive approach utilizing Computational Fluid Dynamics (CFD) and Geographic Information Systems (GIS) to assess dam break risks with a specific focus on the Nagarjuna Sagar earthen dam. The study examines the numerical analysis of water flow dynamics resulting from a dam break. To depict this phenomenon, a two-dimensional numerical model employing the volume of fluid method was developed. The mathematical framework incorporates the Reynolds-averaged incompressible Navier-Stokes equations with the turbulent k-e model and was employed. The computational approach employed in this study is the SIMPLE algorithm. The CFD analysis involved meshing with 42,282 nodes and 41,680 elements, while boundary conditions included one velocity inlet and three pressure outlets open to the atmosphere. The flow was initialized with a 5 m dam site, scaled down at 1:10 (1 meter in the model representing 10 meters in reality). Data were collected for various time intervals (1s, 2s, 2.5s, 3s and 5s), The results of this study reveal the flow velocity patterns following dam break events for the specified time intervals. The outcomes are presented in terms of velocity magnitude vectors, static pressure, dynamic pressure, total pressure, turbulence kinetic energy, volume fraction contours and velocity magnitude profiles at different distances from the dam site (1m, 2m, 5m and 7m). A total of 250 iterations were performed to achieve these results, providing valuable insights into the dynamics of dam break scenarios. This research contributes to a better understanding of the potential consequences of dam failures and aids in improving risk assessment and mitigation strategies for dams.