TY - JOUR
ID - 85466
TI - Comparison of 2-D and 1-D Simulations of Water-Hammer Pressure Pulse Damping Using Steady and Unsteady Friction Terms
JO - Journal of Hydraulics
JA - JHYD
LA - en
SN - 2345-4237
AU - Firoozabadi, B.
AU - Hamedi Nezhad, H.
AD -
Y1 - 2008
PY - 2008
VL - 3
IS - 2
SP - 43
EP - 58
DO - 10.30482/jhyd.2008.85466
N2 - The condition known as water-hammer problem is in fact, a transient condition which may occur as aresult of the worst-case loadings such as pump failures, valve closure in a pipe line system. In suchcases, a positive pressure wave travels upstream and a negative wave downstream from the point ofinterruption. The pressure in the water hammer can vary in such a way that in some cases, it mayincrease and cause destruction to the hydraulic systems. The experimental evidence of dependence offriction on frequency in oscillating flows induced researchers to propose 1-D models in which thiseffect is taken into account explicitly. In fact, the velocity profiles in unsteady flows show greatergradients, and thus greater shear stresses, than the corresponding values in steady flows. 1D- modelapproaches give rise to an under- estimation of the friction forces.In this work, a 2-D model for unsteady transient flow in a pipeline with a reservoir-pipe-valve systemwas simulated for laminar and turbulent flows. In turbulent flow, the Prandtl mixing length was usedfor turbulence modeling. Results of this simulation were compared with the results obtained from the1-D models with steady and unsteady (Brunone model) friction terms. This simulation shows that theunsteady flow phenomena can be more accurately modeled by means of 2-D models, in which thevelocity profiles in the cross section, is taken into account. However, the 2D model is more timeconsuming than 1D model. Through comparisons with the experimental data, results show thatapplying 2D model can improve the magnitude of the predicted duration of the pressure pulse.
UR - https://jhyd.iha.ir/article_85466.html
L1 - https://jhyd.iha.ir/article_85466_608a62830a10658c24c8553b0e13d5fb.pdf
ER -