Author(s): Svetlana Kostic
Linked Author(s): Svetlana Kostic
Keywords: No Keywords
Abstract: A slope break in a supercritical open-channel flow regularly generates a hydraulic jump. The conditions for a jump may not be reached on the channel domain only if the length of a mildly-sloping reach is too short. The conditions under which a supercritical turbidity current undergoes an internal hydraulic jump in response to a slope break are much more complex. Interfacial friction due to entrainment of ambient water acts in the same direction as the bottom friction, slowing down the underflow and promoting the ability of the flow to undergo an internal hydraulic jump. Net deposition (deposition-erosion) on the other hand acts in the same direction as the downslope pull of gravity, suppressing the ability of a supercritical flow to decelerate toward subcritical flow, and display an internal hydraulic jump. The analysis presented here defines the limits on the formation of internal hydraulic jumps in turbidity currents at a slope break. It also provides clear evidence that a hydraulic jump associated with a slope break can under the right conditions leave a clear depositional signature ranging from a single backward-facing step to a coherent train of cyclic steps.
Year: 2009