# One-Dimensional Simulation of Water Hammer in Non-Newtonian Fluids

Document Type : Research Article

Authors

1 Department of Hydraulic Structures, Faculty of Civil Engineering, Jundi shapur university of Technology, Dezful, Iran

2 Faculty of Civil Engineering, Jondi Shapur University of Technology, Dezful, Iran

3 PhD Civil Hydraulics/khozestan/iran

Abstract

Unlike previous studies in Non-Newtonian fluids that use complex two-dimensional models to calculate the velocity gradient in this research, one-dimensional models have been used to calculate Non[1]Newtonian losses that can be implemented faster and have higher execution speeds. The main objective of this research is to study the phenomenon of water hammer in Non-Newtonian fluids of power type (Power Law) using Brunon and Zeilke models. In order to calculate the shear stress in relation to the momentum of the Zeilke and Brunon model, and to solve the equations, the line characteristics of the nonlinear fluid solution have been used. The Brunon model is based on the assumption that the shear stress of the wall changes due to the acceleration of the acceleration, proportional to the acceleration of the fluid. Zilck’s method for calculating the unsteady friction coefficient presents a model based on the analytic integral of convolution. The velocity gradient in the steady state is used to obtain the velocity gradient in the Zeilke model. Finally, numerical results are compared with the results of another research to ensure the accuracy of the solution algorithm. The results of Non-Newtonian fluid modeling show significant changes in pressure values. The proposed formulas, similar to the two-dimensional models, can simulate these changes. As expected in the same continuous flow conditions, the maximum pressure decreases with decreasing viscosity of the fluid. In other words, by decreasing the viscosity of the fluid, the amount of drops across the pipe path will be reduced. According to expectations in the steady flow conditions, the maximum error in the maximum pressure at the valve location is about one percent higher than the two-dimensional state, which, with a decrease in the viscosity of the fluid, causes this error to be close to zero.

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