We report the first observation, in a supersonic flow, of the evolution of the Kelvin-Helmholtz instability from a single-mode initial condition. To obtain these data, we used a novel experimental system to produce a steady shock wave of unprecedented duration in a laser-driven experiment. The shocked, flowing material creates a shear layer between two plasmas at high energy density. We measured the resulting interface structure using radiography. Hydrodynamic simulations reproduce the large-scale structures very well and the medium-scale structures fairly well, and imply that we observed the expected reduction in growth rate for supersonic shear flow.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.115.145001 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Modelling acoustic propagation in realistic ocean through a time-domain environment-resolving ocean model.
J Acoust Soc Am
December 2024
Service Hydrographique et Océanographique de la Marine, Brest, France.
The new generation of non-hydrostatic and compressible numerical models of the ocean can explicitly simulate acoustic waves when and where space and time resolution is adapted. We show that these models can consequently propagate accurately acoustic waves and modes through a free-surface, stratified ocean evolving simultaneously both in space and time, bringing them to the state of the art of acoustic propagation modelling. To some extent, both numerical cost and memory footprint may temper their range of applications but they are an unprecedented tool to evaluate deterministically the effects of ocean variability on low-frequency acoustic propagation in a realistically-evolving ocean.
View Article and Find Full Text PDFInsights into the fluid dynamics of bioaerosol formation in a model respiratory tract.
Biomicrofluidics
September 2024
Department of Mechanical Engineering, Jadavpur University, Kolkata 700032, India.
Article Synopsis
- - Bioaerosols generated in the respiratory system are significant for spreading infectious diseases like common cold, influenza, and COVID-19, highlighting the need to study their production mechanisms.
- - A computational study investigates bioaerosol production resulting from air interacting with a mucus layer in the respiratory tract, revealing that specific fluid dynamics cause instability that can lead to bioaerosol formation.
- - The research finds that bioaerosols can form even during normal breathing, depending on mucus properties, and that these aerosols are larger and less numerous than those produced during coughing, suggesting implications for treatment strategies.
Nonlinear, single-mode, two-dimensional Rayleigh-Taylor instability in ideal media.
Phys Rev E
August 2024
GSI Helmholtzzentrum für Schwerionenforschung Darmstadt, 64291 Darmstadt, Germany.
A model for the single mode, two-dimensional Rayleigh-Taylor instability in ideal, incompressible, immiscible, and inviscid fluids is developed as an extension of a previous linear model based on the Newton's second law [A. R. Piriz et al.
View Article and Find Full Text PDFKelvin-Helmholtz instability as one of the key features for fast and efficient emulsification by hydrodynamic cavitation.
Ultrason Sonochem
August 2024
Faculty of Mechanical Engineering, University of Ljubljana, Askerceva 6, 1000 Ljubljana, Slovenia. Electronic address:
The paper investigates the oil-water emulsification process inside a micro-venturi channel. More specifically, the possible influence of Kelvin-Helmholtz instability on the emulsification process. High-speed visualizations were conducted inside a square venturi constriction with throat dimensions of 450 µm by 450 µm, both under visible light and X-Rays.
View Article and Find Full Text PDFStudy on the Flow Characteristics of Heavy Oil-Water Two-Phase Flow in the Horizontal Pipeline.
ACS Omega
June 2024
School of Oil & Natural Gas Engineering, Southwest Petroleum University, Chengdu 610500, China.
Article Synopsis
- The study addresses the challenges of transporting heavy oil in the Lvda oilfield by examining the flow characteristics of heavy oil-water mixtures in a controlled experimental setup.
- The researchers investigate the transition from stratified flow to annular flow (AF) using specific flow velocity ranges for both oil and water, analyzing how these conditions affect drag reduction.
- Results show that increasing mixing velocity and water content enhances drag reduction, with an optimal ratio yielding significant pressure drop improvements when transporting heavy oil surrounded by water.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!