Experimental Investigation of Gravity Current Frontal Velocity on Rough Beds

Document Type : Research Paper


1 PhD Candidate of Water Structure, Shahid chamran University of Ahwaz

2 Professor of Water Science Faculty, ShahidChamran University, Ahwaz.

3 Associate Professor of Water Science Faculty, ShahidChamran University, Ahwaz


The frontal of gravity current is most important section of these
flowtypes. The advance force in front is pressure gradient due to density
differences between
front flow and
ambient fluid. In order to find the roughness effects as a resistor on frontal
velocity, a series experiment of saline gravity currents were performed on
rough beds with size of 0, 4, 7.5, 12 and 15 (mm). The saline gravity current
with three inflow discharges of 0.7, 1 and 1.3 (lit/s) and three concentrations
of 10, 16, 20 (g/lit)was flowed on slope beds from 0.05 to 2.2 steep
percentage. For estimation of frontal velocity and assessing effects of
parameters, a linear model by correlation coefficient of 0.9 and RMSE of 0.037
and mean ratio deficit of less than 10% was derived. By applying of linear
modeling and linear standardization data, the efficiency index of slop,
relative roughness and non-dimensional discharge (Richardson number) on
prediction of non-dimension frontal velocity was estimated as 0.17,-0.50 and -0.35.