Dynamics of a contrast microbubble between two elastic walls

2012 ◽  
Author(s):  
A. A. Doinikov ◽  
A. Novell ◽  
A. Bouakaz
Keyword(s):  
Elastic Walls

Fluid flow in tubes with elastic walls

1995 ◽  
Vol 165 (2) ◽  
pp. 177-186 ◽  
Author(s):  
Andrei N. Volobuev
Keyword(s):  
Fluid Flow ◽  
Elastic Walls

Modeling Elastic Walls in Lattice Boltzmann Simulations of Arterial Blood Flow

2013 ◽  
Vol 23 (2) ◽  
Author(s):  
Xenia Descovich ◽  
Giuseppe Pontrelli ◽  
Sauro Succi ◽  
Simone Melchionna ◽  
Manfred Bammer
Keyword(s):  
Blood Flow ◽  
Lattice Boltzmann ◽  
Arterial Blood Flow ◽  
Arterial Blood ◽  
Lattice Boltzmann Simulations ◽  
Elastic Walls

scholarly journals Effect of elastic walls on suspension flow

2019 ◽  
Vol 4 (6) ◽  
Author(s):  
Marco Edoardo Rosti ◽  
Mehdi Niazi Ardekani ◽  
Luca Brandt
Keyword(s):  
Suspension Flow ◽  
Elastic Walls

scholarly journals Lamb-type waves generated by a cylindrical bubble oscillating between two planar elastic walls

2016 ◽  
Vol 472 (2188) ◽  
pp. 20160031 ◽  
Author(s):  
A. A. Doinikov ◽  
F. Mekki-Berrada ◽  
P. Thibault ◽  
P. Marmottant
Keyword(s):  
Resonance Frequency ◽  
Surface Waves ◽  
Wave Speed ◽  
Microfluidic Channel ◽  
Scattered Wave ◽  
Channel Height ◽  
Volume Oscillation ◽  
Scholte Wave ◽  
Rigid Walls ◽  
Elastic Walls

The volume oscillation of a cylindrical bubble in a microfluidic channel with planar elastic walls is studied. Analytical solutions are found for the bulk scattered wave propagating in the fluid gap and the surface waves of Lamb-type propagating at the fluid–solid interfaces. This type of surface wave has not yet been described theoretically. A dispersion equation for the Lamb-type waves is derived, which allows one to evaluate the wave speed for different values of the channel height h . It is shown that for h <λ t , where λ t is the wavelength of the transverse wave in the walls, the speed of the Lamb-type waves decreases with decreasing h , while for h on the order of or greater than λ t , their speed tends to the Scholte wave speed. The solutions for the wave fields in the elastic walls and in the fluid are derived using the Hankel transforms. Numerical simulations are carried out to study the effect of the surface waves on the dynamics of a bubble confined between two elastic walls. It is shown that its resonance frequency can be up to 50% higher than the resonance frequency of a similar bubble confined between two rigid walls.

scholarly journals Estimating the diameter of airways susceptible for collapse using crackle sound

2009 ◽  
Vol 107 (5) ◽  
pp. 1504-1512 ◽  
Author(s):  
Arnab Majumdar ◽  
Zoltán Hantos ◽  
József Tolnai ◽  
Harikrishnan Parameswaran ◽  
Robert Tepper ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Tree Model ◽  
Generation Number ◽  
Airway Opening ◽  
Opening And Closing ◽  
Elastic Walls ◽  
Subsequent Injury

Airways that collapse during deflation generate a crackle sound when they reopen during subsequent reinflation. Since each crackle is associated with the reopening of a collapsed airway, the likelihood of an airway to be a crackle source is identical to its vulnerability to collapse. To investigate this vulnerability of airways to collapse, crackles were recorded during the first inflation of six excised rabbit lungs from the collapsed state, and subsequent reinflations from 5, 2, 1, and 0 cmH2O end-expiratory pressure levels. We derived a relationship between the amplitude of a crackle sound at the trachea and the generation number ( n) of the source airway where the crackle was generated. Using an asymmetrical tree model of the rabbit airways with elastic walls, airway vulnerability to collapse was also determined in terms of airway diameter D. During the reinflation from end-expiratory pressure = 0 cmH2O, the most vulnerable airways were estimated to be centered at n = 12 with a peak. Vulnerability in terms of D ranged between 0.1 and 1.3 mm, with a peak at 0.3 mm. During the inflation from the collapsed state, however, vulnerability was much less localized to a particular n or D, with maximum values of n = 8 and D = 0.75 mm. Numerical simulations using a tree model that incorporates airway opening and closing support these conclusions. Thus our results indicate that there are airways of a given range of diameters that can become unstable during deflation and vulnerable to collapse and subsequent injury.

Center-Focus Problem for Discontinuous Planar Differential Equations

2003 ◽  
Vol 13 (07) ◽  
pp. 1755-1765 ◽  
Author(s):  
Armengol Gasull ◽  
Joan Torregrosa
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Critical Point ◽  
Limit Cycles ◽  
New Method ◽  
Polar Coordinates ◽  
Mechanical Problem ◽  
Weak Focus ◽  
Elastic Walls

We study the center-focus problem as well as the number of limit cycles which bifurcate from a weak focus for several families of planar discontinuous ordinary differential equations. Our computations of the return map near the critical point are performed with a new method based on a suitable decomposition of certain one-forms associated with the expression of the system in polar coordinates. This decomposition simplifies all the expressions involved in the procedure. Finally, we apply our results to study a mathematical model of a mechanical problem, the movement of a ball between two elastic walls.

Sign in / Sign up

Export Citation Format

Share Document