On Bounds for the Threshold Pressure Initiating Bubble Growth

1973 ◽  
Vol 95 (1) ◽  
pp. 98-102 ◽  
Author(s):  
Bror Persson
Keyword(s):  
Bubble Growth ◽  
Incompressible Liquid ◽  
Pressure Pulse ◽  
Gas Content ◽  
Upper And Lower Bounds ◽  
Threshold Pressure ◽  
Gas Bubble ◽  
Viscous Incompressible Liquid ◽  
Vanishing Viscosity ◽  
Onset Of Cavitation

Conditions are investigated for the onset of the growth of a spherical gas bubble in a viscous, incompressible liquid. The bubble is assumed to be exposed to a step pressure pulse of infinite duration. It is found that upper and lower bounds for the threshold pressure exist and occur for infinite and vanishing viscosity, respectively. The analysis indicates that the effects of inertia, viscosity, and thermodynamic state of the gas have little influence on the threshold pressure, while the effect of the gas content in the bubble is considerable. The problem considered is to some extent related to the onset of cavitation.

Nuclei and Cavitation

1970 ◽  
Vol 92 (4) ◽  
pp. 681-688 ◽  
Author(s):  
J. William Holl
Keyword(s):  
Bubble Growth ◽  
Scale Effects ◽  
Gas Bubbles ◽  
Gas Content ◽  
Gas Bubble ◽  
Cavitation Nuclei ◽  
The Stability

This paper is a review of existing knowledge on cavitation nuclei. The lack of significant tensions in ordinary liquids is due to so-called weak spots or cavitation nuclei. The various forms which have been proposed for nuclei are gas bubbles, gas in a crevice, gas bubble with organic skin, and a hydrophobic solid. The stability argument leading to the postulation of the Harvey model is reviewed. Aspects of bubble growth are considered and it is shown that bubbles having different initial sizes will undergo vaporous cavitation at different liquid tensions. The three modes of growth, namely vaporous, pseudo, and gaseous are presented and implications concerning the interpretation of data are considered. The question of the source of nuclei and implications concerning scale effects are made. The measurement of nuclei is considered together with experiments on the effect of gas content on incipient cavitation.

Understanding gas bubble trauma in an era of hydropower expansion: how do fish compensate at depth?

2020 ◽  
Vol 77 (3) ◽  
pp. 556-563 ◽  
Author(s):  
Naomi K. Pleizier ◽  
Charlotte Nelson ◽  
Steven J. Cooke ◽  
Colin J. Brauner
Keyword(s):  
Bubble Growth ◽  
Gas Bubble ◽  
Hydroelectric Dams ◽  
Dissolved Gas ◽  
Empirical Relationships ◽  
Lethal Effects ◽  
Exposed Fish ◽  
Total Dissolved Gas ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
The Relationship

Hydrostatic pressure is known to protect fish from damage by total dissolved gas (TDG) supersaturation, but empirical relationships are lacking. In this study we demonstrate the relationship between depth, TDG, and gas bubble trauma (GBT). Hydroelectric dams generate TDG supersaturation that causes bubble growth in the tissues of aquatic animals, resulting in sublethal and lethal effects. We exposed fish to 100%, 115%, 120%, and 130% TDG at 16 and 63 cm of depth and recorded time to 50% loss of equilibrium and sublethal symptoms. Our linear model of the log-transformed time to 50% LOE (R2 = 0.94) was improved by including depth. Based on our model, a depth of 47 cm compensated for the effects of 4.1% (±1.3% SE) TDG supersaturation. Our experiment reveals that once the surface threshold for GBT from TDG supersaturation is known, depth protects rainbow trout (Oncorhynchus mykiss) from GBT by 9.7% TDG supersaturation per metre depth. Our results can be used to estimate the impacts of TDG on fish downstream of dams and to develop improved guidelines for TDG.

scholarly journals Wetting front dynamics in an isotropic porous medium

2012 ◽  
Vol 694 ◽  
pp. 399-407 ◽  
Author(s):  
Yulii D. Shikhmurzaev ◽  
James E. Sprittles
Keyword(s):  
Porous Medium ◽  
Incompressible Liquid ◽  
Porous Matrix ◽  
Viscous Incompressible Liquid ◽  
Pore Scale ◽  
Wetting Front ◽  
Model Case ◽  
New Approach ◽  
Threshold Phenomena ◽  
Front Dynamics

AbstractA new approach to the modelling of wetting fronts in porous media on the Darcy scale is developed, based on considering the types (modes) of motion the menisci go through on the pore scale. This approach is illustrated using a simple model case of imbibition of a viscous incompressible liquid into an isotropic porous matrix with two modes of motion for the menisci, the wetting mode and the threshold mode. The latter makes it necessary to introduce an essentially new technique of conjugate problems that allows one to link threshold phenomena on the pore scale with the motion on the Darcy scale. The developed approach (a) makes room for incorporating the actual physics of wetting on the pore scale, (b) brings in the physics associated with pore-scale thresholds, which determine when sections of the wetting front will be brought to a halt (pinned), and, importantly, (c) provides a regular framework for constructing models of increasing complexity.

Flow of viscous incompressible liquid in a plane channel with abrupt one-sided broadening

1978 ◽  
Vol 35 (6) ◽  
pp. 1470-1474
Author(s):  
V. I. Korobko ◽  
�. M. Malaya ◽  
V. K. Shashmin
Keyword(s):  
Incompressible Liquid ◽  
Plane Channel ◽  
Viscous Incompressible Liquid
Sign in / Sign up

Export Citation Format

Share Document