Dynamic fluid flow behaviour of a tank draining through a vertical tube

Tehrani, Ali; Michael, Patrick; Wragg, A. A.

doi:10.1016/0301-9322(92)90071-n

Cited by 15 publications

(10 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It should be noted that the model developed in this work is only applicable for the fully developed oscillatory¯ow, and thus that it cannot describe the behaviour for very small void fractions or for the large diameter downcomer. In these cases thē ow dynamics is diVerent and is determined by the behaviour of large gas bubbles at the top of the downcomer, as also observed previously [4].…”

Section: Fully Developed Oscillatory¯owmentioning

confidence: 64%

“…The stages of the fully developed oscillatory process can be described intuitively, but they are con®rmed by the experimental observations in this work and the reported observations of the previous investigators [1,4]. The highly simpli®ed stages are shown diagrammatically in Fig.…”

Section: Qualitative Description Of the Processmentioning

confidence: 81%

“…2. Such a system has been investigated previously by Dougall and Kathiresan [1] and Tehrani et al [4], who developed theoretical models of the¯ow processes involved. The models, based on the experimental observations that the¯ow is periodic, assume that thē ow consists of several distinct stages.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Analysis of liquid outflow from single-outlet vessels

Koukouvaos

Kubie

2001

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

The paper presents experimental and theoretical investigation of the out¯ow of liquids from single-outlet vessels incorporating a vertical downcomer. In such vessels the liquid leaving through the outlet of the downcomer is replaced by another¯uid, which enters the vessel± downcomer system through the same opening. Experimental results of the variation of the void fraction and pressure in the vessel with elapsed time are presented. It is shown that the¯ow is generally oscillatory, and the conditions required for the establishment of the fully developed oscillatory¯ow are reported. A theoretical model of the fully developed oscillatory¯ow is developed. The model describes well the frequency of the oscillatory¯ow and the variation of the gas void fraction in the vessel with elapsed time. The model somewhat overpredicts the amplitude of the pressure oscillations. Thermodynamic aspects of this¯ow are also considered.

show abstract

Section: Fully Developed Oscillatory¯owmentioning

confidence: 64%

Section: Qualitative Description Of the Processmentioning

confidence: 81%

See 1 more Smart Citation

Analysis of liquid outflow from single-outlet vessels

Koukouvaos

Kubie

2001

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

show abstract

“…Another aspect worthy of investigation would consist in examining the influence of the neck's length. As shown by Tehrani et al (1992) , increasing this length may change the dynamics of oscillations by adding a large pressure loss in the system. How these changes are reflected in the dynamics of bubbles released from the neck is unknown and could be investigated with the methods employed here.…”

Section: Summary and Concluding Remarksmentioning

confidence: 99%

“…These studies focused on small d * , a condition under which the flow exhibits an on-off oscillatory behavior. Tehrani et al (1992) proposed a model aimed at predicting the pressure fluctuation amplitude in the top air buffer in an idealized configuration. In their work, the bottle is reduced to a cubic tank, with a typical size of 25 cm, and the neck to a 60 cm long straw with a diameter up to 25 mm, i.e.…”

Section: Introductionmentioning

confidence: 99%

Emptying of a bottle: How a robust pressure-driven oscillator coexists with complex two-phase flow dynamics

Mer

Praud

Magnaudet

et al. 2019

International Journal of Multiphase Flow

View full text Add to dashboard Cite

The emptying of a bottle is one of the most common two-phase flows encountered in everyday's life fluid mechanics. We report on a detailed experimental analysis of this flow configuration covering a wide range of neck-to-bottle diameter ratios, d * , and initial filling ratios, F. The joint use of a pressure sensor at the top of the bottle and a shadowgraph technique to track the evolution of the upper liquid surface allows the average gas volume fraction in the fluid column to be computed throughout the discharge. Variations of the bottle emptying time, gas content, and characteristics of the pressure signal as a function of d * and/or F are analyzed, and scaling or evolution laws are derived. A specific focus is put on the initial transient stages following the neck opening, especially on the nature and growth of the first bubble that reaches the upper free surface. Over a wide range of d * , this bubble takes the form of a large spherical cap or Taylor bubble, the rise speed of which is controlled by the bottle diameter. Such a bubble directly emerges from the neck for large enough d * , but rather results from successive coalescence of smaller bubbles for small d *. Whatever d * , the volume of this leading bubble increases over time, since a fraction of the small bubbles swarm trailed in its wake merges with its back face. This coalescenceinduced growth is quantified through a simple model.

show abstract