A bubble reaching an air-liquid interface usually bursts and forms a liquid jet. Jetting is relevant to climate and health as it is a source of aerosol droplets from breaking waves. Jetting has been observed for large bubbles with radii of R≫100 μm. However, few studies have been devoted to small bubbles (R<100 μm) despite the entrainment of a large number of such bubbles in sea water. Here we ...

Squids encounter vastly different flow regimes throughout ontogeny as they undergo critical morphological changes to their two locomotive systems: the fins and jet. Squid hatchlings (paralarvae) operate at low and intermediate Reynolds numbers (Re) and typically have rounded bodies, small fins, and relatively large funnel apertures, whereas juveniles and adults operate at higher Re and generall...

The human cough is a significant vector in the transmission of respiratory diseases in indoor environments. The cough flow is characterized as a two-stage jet; specifically, the starting jet (when the cough starts and flow is released) and interrupted jet (after the source supply is terminated). During the starting-jet stage, the flow rate is a function of time; three temporal profiles of the e...

Temperature fluctuation in fluid causes high cycle thermal fatigue in shroud structure according to its amplitude and frequency. There are still some incidents of thermal fatigue and leakage in light water reactors (Japanese PWR Tomari-2 in 2003, French PWR CIVAUX in 1998), and also in sodium cooled reactors (French FBR PHENIX in 1992). Mixing tee is a typical component where temperature fluctu...

Quenching cooling rate of rotary hollow cylinder by one row of water impinging jets has been experimentally studied. Water jets (d = 8 mm) with sub-cooling 55 to 85 ◦C and Reynolds number 8,006 to 36,738 impinged over rotary hot hollow cylinder (rotation speed 10 to 70 rpm) with initial temperature 250 to 600 ◦C. Impingement impact angle of row of jets varied between 0 to 135 ◦ and jet-to-jet s...

Fast-swimming hydromedusan jellyfish possess a characteristic funnel-shaped velum at the exit of their oral cavity that interacts with the pulsed jets of water ejected during swimming motions. It has been previously assumed that the velum primarily serves to augment swimming thrust by constricting the ejected flow in order to produce higher jet velocities. This paper presents high-speed video a...

This paper depicts the structural design of a novel water-jet-based spherical underwater robot. The propulsion system is made up of four water-jet thrusters and 8 steering servo motors which can adjust the polydirectional shift of thrusters nozzle to achieve 4-degrees-of-freedom (4-DOF) motion. Every two thrusters nozzles formed an angle of 90 degree in one plane. A bilayer structure was adopte...

1EPA 2Printed on paper that contains at least 30 percent postconsumer fiber. 1 This fact sheet focuses on contrails produced by aircraft engine exhaust. However, the term " contrail " is also used to refer to the short trails sometimes briefly appearing over aircraft wings or engine propellers, especially under mild, humid conditions. These contrails consist entirely of atmospheric water that c...