SIMULATION OF TURBULENT FLOW THROUGH TARBELA DAM TUNNEL 3

Tarbela dam is one of the largest earth filled dam in the world. The inflow of sediments in the Tarbela reservoir has resulted in reduction in water storage capacity. During recent years, a reasonable increase of sediment particles in the tunnel has been observed. This is damaging to the tunnels, power generating units and is a severe threat to the plant equipment. To the authors knowledge, to-date no comprehensive simulation studies have been performed for flooding in the reservoir or turbulent flows in the tunnels. In this paper, turbulent flow in Tunnel 3 of the Tarbela Dam is analyzed using Reynolds Stress Model with and without considering the effect of sediments particle. Results are presented for three different water heads in the reservoir i.e. considering summer, winter and average seasons and for one-way and two-way/full coupling for sediments particle tracking/deposition. The effect of cavitation erosion and damage to the tunnels due to erosion is investigated and results are compared with the experimental erosion results for similar geometries and are found to be in good agreement. Sediments particulate analysis is also performed for the validation of the samples collected from WAPDA (water and power development authority). Moreover, pressure, velocity and erosion rate results are discussed to get complete behavior of the turbulent flow of water in the tunnel.