Mixing and transport driven by oscillatory waves of small intestine wall

The mixing and transport of different substances in the intestinal contents are driven by patterned fluctuation waves in the intestinal wall, generated by the contractions of circular and longitudinal muscle fibers within the muscularis propria. The primary types of waves include peristaltic, segmental, and pendular waves. Through high-fidelity numerical simulations based on the lattice Boltzmann method, the mixing and transport induced by different types of waves under a wide range of parameter conditions have been thoroughly investigated. The results indicate that the fluctuation waves in the intestinal wall can create diverse flow patterns, shear distributions, and mixing modes within the intestine by altering the wave frequency and amplitude. Furthermore, the combination of different types of waves, as well as waves of the same type with varying parameters, can produce more complex flow patterns. This suggests that human body may actively regulate the mixing and transport processes within the small intestine by controlling intestinal motility.