Microchannel heat sinks typically consist of parallel channels connected through a common header. During flow boiling random temporal and spatial formation of vapor bubbles may lead to reversed flow in certain channels which causing an early CHF condition. Inside the microchannels the liquid surface tension forces is expected to play an important role and impact the vapor bubble growth and corr...

Two-phase microchannel heat sinks are promising for future thermal management of integrated circuit (IC) chips. The modeling and design of these heat sinks, however, require a comprehensive understanding of the interplay between vapor bubble nucleation and growth and the associated liquid velocity field. Most of the flow visualization studies for two-phase convection in microchannels have provi...

Visualization study of bubble growth with multiple tangential nozzles is investigated in a bubble absorber. Bubble behavior is studied with different flowing condition like still, co-current and counter-current flow of water. Effect of air flow rate, water flow rate, nozzle diameters, number of nozzles and orientation of nozzle angle with reference to vertical plane on bubble diameter is studie...

The standard treatment of altitude decompression sickness (aDCS) caused by nitrogen bubble formation is oxygen breathing and recompression. However, micro air bubbles (containing 79% nitrogen), injected into adipose tissue, grow and stabilize at 25 kPa regardless of continued oxygen breathing and the tissue nitrogen pressure. To quantify the contribution of oxygen to bubble growth at altitude, ...

This paper analyses adiabatic gas bubble formation, growth, and detachment which are produced from a submerged needle in water with the aim of elucidating the impact of surface tension on bubble properties. A simulation model is utilized to enable examination of the problem for the mentioned parameter. The numerical results are compared with experimental observations on the bubble for validatio...

We consider the Rayleigh–Taylor instability in the early evolution of the rarefied radio bubbles (cavities) observed in many cooling–flow clusters of galaxies. The top of a bubble becomes prone to the Rayleigh–Taylor instability as the bubble rises through the intra–cluster medium (ICM). We show that while the jet is powering the inflation, the deceleration of the bubble–ICM interface is able t...

Laser-induced bubbles can be caused by an optical breakdown in water. They are a result of the optodynamical process where the energy of a high intensity laser pulse is converted into the mechanical energy through an optodynamic conversion. At this process the absorbed optical energy causes plasma expansion that in turn initiates dynamic phenomena: spreading of a shock wave and the development ...

This article introduces a method for microscale assembly using laser-activated bubble latching. The technique combines the advantages of directed fluidic assembly and surface tension-driven latching to create arbitrarily complex and irregular structures with unique properties. The bubble latches, generated through the laser degradation of the tile material, are created on the fly, reversibly li...

How did the Federal Reserve Bank react to the stock market bubble of the late 1990s? At a Symposium sponsored by the Federal Reserve Bank of Kansas City in Jackson Hole, Wyoming on August 30, 2002, Chairman Alan Greenspan remarked that economists do not currently have a way to measure a stock market bubble convincingly. He also argued that in the absence of such a measure, it was difficult for ...

Digital Image Analysis (DIA) has been employed to characterize the time evolution of a bubble injected from a single orifice into a pseudo 2-dimansional gas-solid fluidized bed. The injected bubble diameter increased with the square root of time before detachment. During bubble free flight in the bed, its diameter remains approximately constant. The center of mass of the bubble increases with t...