Vol 73, No 4 (2022)
Original article
Published online: 2022-12-28

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Pulsatile gas-liquid flow resembling Decompression Sickness: Computational Fluid Dynamics simulation and experimental validation

Sotiris Evgenidis1, Thodoris Karapantsios1
Pubmed: 36583406
IMH 2022;73(4):189-198.


Background: This work performs two-dimensional Computational Fluid Dynamics (CFD) simulations of pulsatile
bubbly flow in a column resembling the flow inside human vena cava during Decompression Sickness
(DCS), aiming to illustrate the effect of certain parameters in bubbly blood flow and so facilitate the design
of the: a) corresponding in-vitro bubbly flow experiments under pulsatile flow conditions inside a flow loop
and b) in-vivo trials on swines for assessing a novel electrical impedance spectroscopy technique on the
detection of bubbles (as those found during DCS) in their bloodstream.

Materials and methods: The commercially available ANSYS 2019-R3 CFD code was employed to simulate
the pulsatile bubbly flow that resembled DCS. Simulations were validated against experiments conducted
in a vertical co-current upward pulsatile bubbly flow provided by a flow loop equipped with electrical, optical
and pressure diagnostics.

Results: CFD simulations under pulsatile conditions were initially validated by oscillatory in-vitro bubbly
flow experiments. Then, the influence of pulsation parameters on void fraction, α, and flow velocity, U,
profiles was computationally investigated. Intense periodic fluctuations of void fraction were observed
along the column and their intensity increases with pulsation amplitude. Moreover, U and α radial profiles
were uniform for bubbles 30 μm but showed a core-peaking profile for bubbles 300 μm.

Conclusions: CFD simulations of pulsatile bubbly flow resembling DCS provided unconventional information
about the influence of different-sized sub-millimetre bubbles on the flow velocity and void fraction profiles,
which are expected to improve the design of in-vitro and in-vivo trials for the detection of bubbles such as
those found in DCS.

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