Three‐dimensional submerged wall jets and their transition to density flows: Morphodynamics and implications for the depositional record

Jets that expand from an orifice into ambient water body represent a basic flow model for depositional environments related to expanding flows. Momentum-dominated jets evolve gravity-dominated density To understand this transition and its sedimentological relevance, three-dimensional tank experiments with submerged wall were conducted, systematically varying parameters such as the initial difference, bed slope, grain size sediment supply. Bedform successions could be subdivided those jet flow. Jet deposits included early-stage bedforms, scours mouth bars. Early-stage bedforms are asymmetrical dunes spread concentrically orifice. Sediment entrainment by eddies led formation of Flows lesser difference produced more elongate scours. Conversely, became deeper denser incoming Coarser-grained caused higher steeper bars vice versa. The momentum-dominated flows occurred approximately at mouth-bar crest. Hydraulic jumps absent in regions transitions Instead, complex patterns circulations inferred velocity measurements within scour crests. trains controlled Coarse-grained high supply rates strong aggradation splitting, leading bedform laterally adjacent bar. Fine-grained low downflow symmetrical deposited always displayed in-phase relationship flow, indicating they antidunes. experimental resemble known subaqueous ice-contact fans deep channel-lobe zones.