The growth of a vapour bubble in a superheated liquid of variable surface tension and viscosity between two finite boundaries is introduced. The problem is solved analytically using the modified method of Plesset and Zwick method. The pressure difference is described in terms of temperature difference and initial pressure difference. The surface tension, viscosity, and initial and final time of...

This paper reports the first study of the O VI resonance line emission (λλ 1032, 1038) originating in the Local Bubble (or Local Hot Bubble) surrounding the solar neighborhood. In spite of the fact that O VI absorption within the Local Bubble has been observed, no resonance line emission was detected during our 230 ksec Far Ultraviolet Spectroscopic Explorer observation of a " shadowing " filam...

This report details work done by the author during a six month secondment from Schlumberger Cambridge Research to Intevep during April to October 1997. A mathematical description for the flow within a porous permeable medium of oil containing dissolved gas, and capable of liberating that gas when the pressure is dropped to form small bubbles or regions of connected gas, is presented. The intent...

An experimental study was conducted to characterize the transient behavior of laminar flow separation on a NASA low-speed GA (W)-1 airfoil at the chord Reynolds number of 70,000. In addition to measuring the surface pressure distribution around the airfoil, a high-resolution particle image velocimetry (PIV) system was used to make detailed flow field measurements to quantify the evolution of un...

For the operation of high void fraction bubbly flows in bubble columns, insight in primary parameters such as bubble size, shape and velocity as well as gas volume fraction is essential. At high gas volume fractions the flow system becomes opaque, ruling out non-intrusive optical techniques. As an alternative optical fibre probes can be used, which have the advantage of low cost, simplicity of ...

The problem of predicting the moments of the distribution of bubble radius in bubbly flows is considered. The particular case where bubble oscillations occur due to a rapid (impulsive or step change) change in pressure is analyzed, and it is mathematically shown that in this case, inviscid bubble oscillations reach a stationary statistical equilibrium, whereby phase cancellations among bubbles ...

A theoretical model for bubble formation and weeping has been developed. Potential #ow theory is used to describe bubble formation at the ori"ce. The in#uence of detached, rising bubbles on liquid pressure at the ori"ce is predicted by Oseen's modi"cation to potential #ow. Model predictions of bubble volumes, weeping #ow rates and weep points agree well with experimental results. ( 2000 Elsevie...

The present study considers of the water and air flow and Micro-Bubble production inside the venturi tube, by the use of dimensional analysis. Numerical analysis of Micro-Bubble creation in venturi tube requires fast computers and large amounts of storage space. Up to now, there has been no numerical analysis concerning Micro-Bubble creation and all other existing studies are experimental. To s...

Bubble formation at two, three, four and six symmetrical ori&ces has been investigated by high-speed photography and analysis of chamber pressure 6uctuations. Regimes of synchronous, alternative and unsteady bubbling were clearly identi&ed, and the e7ects of ori&ce spacing and liquid depth on bubbling synchronicity and frequency were studied. Theoretical predictions of bubble frequency and aver...