%0 Journal Article
%T Core impact force of vertical water jets on smooth and rough surfaces
%J Scientia Iranica
%I Sharif University of Technology
%Z 1026-3098
%A Fathi-Moghadam, Manoochehr
%A Salemnia, Amin
%A Kiani, Sajad
%D 2019
%\ 04/01/2019
%V 26
%N 2
%P 690-698
%! Core impact force of vertical water jets on smooth and rough surfaces
%K Breakup length
%K Falling height
%K Pressure coefficient
%K Turbulence Intensity
%K Vertical jet
%R 10.24200/sci.2017.4522
%X A normal way to dissipate energy of the dam released high velocity jets is to allow them to free-fall in to a plunge pool or impact a plane surface in case of dam site limitations. The water jets have an undisturbed core from nozzle outlet to a certain falling height, which has more impact force and less turbulent intensity than the developed part of the free jet. Experiments are conducted to determine core impact pressure coefficient of a vertical jet on smooth and rough plane surfaces. The experiment results for different jet diameters and falling heights showed considerable increase of the mean dynamic pressure coefficient with increase of the jet Froude number for both smooth surface and rough surface. A simple Froude based mathematical model is correlated for estimation of jet core impact force on the smooth and rough plane surfaces. In addition, a considerable increase of the jet core length was indicated with increase of the jet Froude number. Results also showed a strong correlation between turbulence intensity coefficient and the jet core length.
%U http://scientiairanica.sharif.edu/article_4522_2a499481111eba1b7d2a033d6f6875fe.pdf