Dynamics of endoscopy on the peristaltic flow of non-Newtonian fluid through an annulus region between two flexible tubes with Soret and Dufour effects

Abstract

Endoscopes play a vital role in diagnosing and treating medical conditions, especially in organs that rely on peristaltic motion for fluid transport, such as the stomach and intestines. Therefore, this study explores how an endoscope affects the peristaltic movement of a hyperbolic tangent fluid within an annular region formed by two cylinders. The inner cylinder is flexible, following a sinusoidal wave pattern, while the outer cylinder remains rigid and moves at a constant velocity. The mathematical model is developed using the long-wavelength approximation and low Reynolds number assumptions, simplifying the complex fluid dynamics. The energy equation accounts for thermal radiation and heat absorption or release from a heat sink/source, while the mass transfer equation incorporates Soret (thermal diffusion) and Dufour (diffusion-thermo) effects. Analytical solutions for velocity, pressure gradient, temperature, concentration, and streamlines are derived using a perturbation method. Graphical analysis reveals that increasing Soret and Dufour numbers enhances temperature distribution by promoting heat transfer but reduces fluid concentration due to stronger diffusion effects. These results have significant medical applications, particularly in optimizing endoscopic procedures for diagnosing internal organ disorders. Additionally, the findings emphasize how pressure gradient variations can regulate fluid flow rates, which is crucial for procedures like catheter insertion in arteries where precise flow control is essential.