This study investigated the hydrodynamic instability on a liquid-gas interface and its dependence on initial conditions.A drop tower method was employed to generate a quasi-single-mode water-air interface and also fin...This study investigated the hydrodynamic instability on a liquid-gas interface and its dependence on initial conditions.A drop tower method was employed to generate a quasi-single-mode water-air interface and also finite pulse accelerations.The finite pulse was produced by releasing a water tank onto coil springs,achieving a peak acceleration of 193 times the gravity acceleration within 5 ms.The experiments highlighted the transition from Rayleigh-Taylor(RT)stabilization to near Richtmyer-Meshkov(near-RM)instability.The results demonstrated that bubble and spike development is dominated by RT stabilization during pulse acceleration and near-RM instability after pulse.The different behaviors of bubbles and spikes under high-Atwood-number conditions were observed,noting perturbation phase reversals and the formation of a high-speed water jet.Spectral analysis of the interface contour and time-varying Fourier mode amplitudes revealed that the bubble development is suppressed by nonlinear effect while the spike instability is markedly enhanced by flow focusing.A sink-flow model was developed to evaluate the water jet velocity induced by the depthwise flow focusing,validated through impact experiments on an initially unperturbed interface.Finally,a comprehensive nonlinear solution was established for quantifying the hydrodynamic instabilities on a water-air interface,incorporating variable acceleration,nonlinear effects,and flow focusing.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12388101,12572256,12441203,and 24FAA00998).
文摘This study investigated the hydrodynamic instability on a liquid-gas interface and its dependence on initial conditions.A drop tower method was employed to generate a quasi-single-mode water-air interface and also finite pulse accelerations.The finite pulse was produced by releasing a water tank onto coil springs,achieving a peak acceleration of 193 times the gravity acceleration within 5 ms.The experiments highlighted the transition from Rayleigh-Taylor(RT)stabilization to near Richtmyer-Meshkov(near-RM)instability.The results demonstrated that bubble and spike development is dominated by RT stabilization during pulse acceleration and near-RM instability after pulse.The different behaviors of bubbles and spikes under high-Atwood-number conditions were observed,noting perturbation phase reversals and the formation of a high-speed water jet.Spectral analysis of the interface contour and time-varying Fourier mode amplitudes revealed that the bubble development is suppressed by nonlinear effect while the spike instability is markedly enhanced by flow focusing.A sink-flow model was developed to evaluate the water jet velocity induced by the depthwise flow focusing,validated through impact experiments on an initially unperturbed interface.Finally,a comprehensive nonlinear solution was established for quantifying the hydrodynamic instabilities on a water-air interface,incorporating variable acceleration,nonlinear effects,and flow focusing.
