Respiratory Droplet Motion, Evaporation and Spread of COVID-19-Type Pandemics

It is well established the COVID-19 virus is transmitted via respiratory droplets. Consequently, much research targets better understanding droplet motion and evaporation. In Physics of Fluids, researchers developed a mathematical model for the early phases of a COVID-19-like pandemic using the aerodynamics and evaporation characteristics of respiratory droplets. The researchers modeled the pandemic dynamics with a reaction mechanism and then compared the droplet cloud ejected by an infected person versus one by a healthy person.

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Bubble Dynamics Reveal How to Empty Bottles Faster

Researchers from the Indian Institute of Technology Roorkee have discovered how to make bottles empty faster, which has wide-ranging implications for many areas beyond the beverage industry. In this week’s Physics of Fluids, they explore this bottle-emptying phenomenon from the perspective of bubble dynamics on a commercial bottle by using high-speed photography. Image analysis allowed them to conceptualize various parameters, such as liquid film thickness, bubble aspect ratio, rise velocity and bottle emptying modes.

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Simulations Show Effects of Buoyancy on Drift in Florida Current

Acquiring a better understanding for how objects drift in the ocean has importance for many uses, but most models lack a systematic approach. One new effort looks to provide a clearer alternative. Researchers have released the results from an experiment aimed at tracking different objects as they drift in the Florida Current. Using satellite data, the group developed a new model for how objects drift. They discuss their work in this week’s Physics of Fluids.

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Following the lizard lung labyrinth

Mammals inhale oxygen-rich air and they exhale depleted air, exhibiting a so-called tidal flow pattern. In contrast, bird breath travels through part of the respiratory system, but in a one-way loop throughout most of the lung. Biologists have discovered that Savannah monitor lizards have lung structures that are hybrid system of bird and mammal lungs.

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Insects’ Drag-Based Flight Mechanism Could Improve Tiny Flying Robots

Thrips don’t rely on lift in order to fly. Instead, the tiny insects rely on a drag-based flight mechanism, keeping themselves afloat in airflow velocities with a large ratio of force to wing size. In a study published in this week’s Journal of Applied Physics, researchers performed the first test of the drag force on a thrip’s wing under constant airflow in a bench-top wind tunnel. Drawing from experience in microfabrication and nanomechanics, they created an experiment in which a thrip’s wing was glued to a self-sensing microcantilever.

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Gallery of Fluid Motion: Capturing Liquids and Gases in Action

Tears stream down your face. A beer flows down the side of a pint glass. Fluid mechanics is central to understanding the world around us. The beauty of fluid motion was on display last week in Seattle, where more than 3,000 scientists gathered for the 72nd Annual Meeting of the American Physical Society’s Division of Fluid Dynamics. Created in 1987, the Gallery of Fluid Motion (GFM) is the premier visual record of contemporary fluid mechanics.

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Schedule for the APS DFD Press Conferences with Live Webcasts from Seattle

Press conferences for the 72nd Annual Meeting of the American Physical Society Division of Fluid Dynamics in Seattle will be held Monday, Nov. 25, at the Washington State Convention Center. The conferences, which will be webcast, will focus on research into how flow control is making some MLB pitchers nearly unhittable, predicting tornado formation from the sounds that storms make and teaching fluid mechanics through dance, as well as other discoveries in fluid dynamics.

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Fluid Dynamics Provides Insight into Wildfire Behavior

The Kincade Fire has been burning through Sonoma County, displacing people from their homes and leaving destruction in its wake. It is a stark reminder of the increasingly pressing need for a better understanding of how fires begin and spread. This is where Rodman Linn and his research come in. He develops and uses computational models of the coupled interaction between the wildfires and surrounding atmosphere at Los Alamos National Laboratory. In the November 2019 issue of Physics Today, Linn describes a few of the many ways that fluid dynamics controls the behavior of fires.

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Analysis of Galileo’s Jupiter Entry Probe Reveals Gaps in Heat Shield Modeling

The entry probe of the Galileo mission to Jupiter entered the planet’s atmosphere in 1995 in fiery fashion, generating enough heat to cause plasma reactions on its surface. The data relayed about the burning of its heat shield differed from the effects predicted in fluid dynamics models, and new work examines what might have caused such a discrepancy.

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Stabilizing Multilayer Flows May Improve Transportation of Heavy Oils

During the past 20 years, the oil industry has begun to transition away from light oils toward heavier oils. But transporting heavy oils cost-effectively is a challenge because heavy oils are viscous — essentially a thick, sticky and semifluid mess. One way to outmaneuver this problem, reported in Physics of Fluids, is a viscoplastic lubrication technique.

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