Numerical investigation of thermo-physical properties of non-newtonian fliud in a modelled intestine

Abstract

Several kinds of researches have been conducted on peristaltic flow of non-Newtonian fluid in modelled oesophagus, stomach and intestine. However, further investigation is still needed es- pecially in the area of mechanical shear stress, the influence of inlet temperature and velocity, Nutsselt number and the history of strain rates experienced by fluid particles. This study presents the numerical investigation of thermo-physical properties of non-Newtonian fluid in a modelled intestine. The properties investigated were fluid temperature, velocity, Nutsselt number and wall shear stress. Numerical simulation was performed by solving 3D Navier-Stokes and continuity equations. The intestinal model was drawn by using Autodesk Inventor 2017 while the numerical investigation was conducted by using ANSYS FLUENT 16.0. The Computational Fluid Dynamics solver employs the Finite Element Method (FEM) to discretize the governing equations. Chyme, Hibiscus Sabdariffa Roselle (Sobo), Soymilk (Soya) and Pap (Ogi) were the working fluids used for the investigation. Analyses of the results showed that the variation of fluid temperature and heat transfer with axial position across the length of intestinal model were not significantly influenced by the variation of the inlet velocity. Expansion of the model about the pulsating part enhanced heat transfer and nutrient delivery to the intestinal walls. Variation of the inlet velocity did not affect the average Nutsselt number. Chyme and Sobo had the highest and lowest Nutsselt number, respectively. Sobo displayed the best fluid properties considering flow behaviour while Soya dis- played the best properties for thermal history. The results presented in this study are of countless importance in medical, paramedical, engineering applications, thermoregulation system, ther- motherapy, and biomedical disciplines, where analyses and investigation of gastrointestinal tract history can be understudied.