Paper Title
Numerical Simulation of Unsteady Flow Due to Dam Break

To analyze and fully understand the natural phenomena such as unsteady flow phenomena resulting from dam Break, developing of numerical models that can simulate the boundary conditions on the free surface flows with large displacement that can and also deepen our understanding of the physical details of the interaction process of dam defeat waves is of great importance. The purpose of this study is to analyze the hydrodynamic flow of the dam Break in vertical two-dimensional way using fluent software and solving Navier-Stokes equations. This is achieved by collecting and processing all the necessary information, the correct definition of the physical model is presented. Then using test and comparison, the optimized parameters of the network size, suitable turbulence model and the turbulence term (plan) was determined for different separation. Then, the values of the dimensionless wave front position with the passage of time and the values of dimensionless water depth and pressure in certain sections have been calculated. To evaluate the model and the equations used, the simulation results were validated with experimental results and other numerical methods in the literature. Comparison results show the high accuracy and reliability of the method used. Based on the findings of this study it was proved that Fluent Model has great capabilities in simulation of analysis and evaluation the phenomenon of dam Break. In addition, it has the possibility of adaptation to different conditions and limitations of different problems. And after creating a model in the software environment, the effects of following scenarios on it can easily be observed: Effect of downstream slope of the dam in the reservoir on negative wave The effect of input varying with time (hydrograph) on the negative wave created in the tank The effect of the initial depth on the progress of flow created by flood at the time of Break Two important parameters' influence the grid size and time step option on results The effect of velocity gradients in the tank drain Software inflow effect on results at 6 and 8 seconds Effect of substrate roughness and depth of the coastal on the wave progress due to dam Break Keywords- Dam Break Flows, Fluent, Simulation, Turbulence Model..., Barrier-free Flow