Author(s): Jun Fan; Aifeng Tao; Jinhai Zheng
Linked Author(s): Jinhai Zheng
Keywords: Open channel flows; Shallow flows; Rippled bottoms; Resonant interaction; Instability
Abstract: Resonant interaction among free-surface waves, ambient currents, and rippled bottoms will be induced when shallow open-channel flow over continuous rippled patches at certain specific conditions. Under these conditions, new free-surface wave components could be triggered from the resonance, which was observed in flume experiments for steady free-surface open channel flow over rippled bottoms. For instance, as one of the representative hydrodynamics phenomena in shallow flow, the upstream-propagating waves have been investigated by flume experiment and theoretical analysis to identify the generation mechanism. This hydrodynamic phenomenon could be induced in estuarial areas potentially. With the existence of large-scale continuous submarine sandbars and tidal/runoff currents, this kind of wave stimulation might affect the wave field if it is triggered. However, the generation of this new wave component on the free surface not only depends on the triad resonant condition but also relies on some specific critical conditions (i.e., the critical flow velocity of wave energy stagnation for upstream-propagating waves). There are still unknown mechanisms for higher-order resonance with complex resonance.
Year: 2025