Abstract: A vertical two-dimensional RNG k-ε turbulent model is established and its reasonability and accuracy are verified by comparison with existing experimental data. Density current on a slope in the presence of different slope gradients and discharges is simulated, and results reveal that 1) the head velocity of density current has a function relationship with the slope gradients, and there is an optimal slope gradients which maximizes the head velocity under the same condition; 2)the relation between head velocity and the cubic root of buoyance flux is not a strict proportional function, deviating under small or large discharge; 3)the head shape is enlarged in the motion process of density current, and the ratio of thickness to length of the head decreases gradually; 4)the growth rate of the head increases with the increase of slope gradients and discharges, and finally tends to a steady rate. These results could help further understand the motion pattern of density current on slope.

Key words: density current, slope, head velocity, numerical simulation, RNG k-ε turbulent model