TY - JOUR
T1 - Relationship between gastric motility and liquid mixing in the stomach
AU - Miyagawa, Taimei
AU - Imai, Yohsuke
AU - Ishida, Shunichi
AU - Ishikawa, Takuji
N1 - Funding Information:
This research was supported by Japan Society for the Promotion of Science, KAKENHI Grants 25000008, 26600151, 15J02376, and 16H03187
Publisher Copyright:
© 2016 the American Physiological Society.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016
Y1 - 2016
N2 - The relationship between gastric motility and the mixing of liquid food in the stomach was investigated with a numerical analysis. Three parameters of gastric motility were considered: the propagation velocity, frequency, and terminal acceleration of peristaltic contractions. We simulated gastric flow with an anatomically realistic geometric model of the stomach, considering free surface flow and moving boundaries. When a peristaltic contraction approaches the pylorus, retropulsive flow is generated in the antrum. Flow separation then occurs behind the contraction. The extent of flow separation depends on the Reynolds number (Re), which quantifies the inertial forces due to the peristaltic contractions relative to the viscous forces of the gastric contents; no separation is observed at low Re, while an increase in reattachment length is observed at high Re. While mixing efficiency is nearly constant for low Re, it increases with Re for high Re because of flow separation. Hence, the effect of the propagation velocity, frequency, or terminal acceleration of peristaltic contractions on mixing efficiency increases with Re.
AB - The relationship between gastric motility and the mixing of liquid food in the stomach was investigated with a numerical analysis. Three parameters of gastric motility were considered: the propagation velocity, frequency, and terminal acceleration of peristaltic contractions. We simulated gastric flow with an anatomically realistic geometric model of the stomach, considering free surface flow and moving boundaries. When a peristaltic contraction approaches the pylorus, retropulsive flow is generated in the antrum. Flow separation then occurs behind the contraction. The extent of flow separation depends on the Reynolds number (Re), which quantifies the inertial forces due to the peristaltic contractions relative to the viscous forces of the gastric contents; no separation is observed at low Re, while an increase in reattachment length is observed at high Re. While mixing efficiency is nearly constant for low Re, it increases with Re for high Re because of flow separation. Hence, the effect of the propagation velocity, frequency, or terminal acceleration of peristaltic contractions on mixing efficiency increases with Re.
KW - Computational biomechanics
KW - Gastric flow
KW - Gastric mixing
KW - Realistic geometry
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U2 - 10.1152/ajpgi.00346.2016
DO - 10.1152/ajpgi.00346.2016
M3 - Article
C2 - 27789458
AN - SCOPUS:85006265409
VL - 311
SP - G1114-G1121
JO - American Journal of Physiology - Gastrointestinal and Liver Physiology
JF - American Journal of Physiology - Gastrointestinal and Liver Physiology
SN - 0193-1857
IS - 6
ER -