Effects of Surface Roughness on Transient Viscoelastic Fluids Flow Driven by Peristaltic Pumping

Abstract

Present study investigates the impact of sinusoidal surface roughness on the behaviour of viscoelastic fluid being transported in physiological vessels by peristaltic pumping, a vital mechanism in biological systems, and can be applied in industrial processes. Most of the biological surfaces are smooth however it is not complete smooth and some roughness is always present. To understand and examine the roughness effects and viscoelastic behaviour, a mathematical model is developed, incorporating a low Reynolds number and long-wavelength approximation. In this study, viscoelastic fluid behaviour is analysed by considering the Jeffrey model. The study focuses on the effects of the ratio of relaxation time to the retardation time and roughness height on key fluid characteristics, including axial velocity, pressure gradient, pressure distribution, volumetric flow rate and skin friction. The results reveal that increased surface roughness height leads to a reduction in fluid flow, as indicated by decreased axial velocity, volumetric flow rate and increased pressure gradient. Conversely, an increase in surface roughness height elevates skin friction, highlighting the additional resistance encountered by the fluid. These findings are critical for optimizing fluid transport systems that involve viscoelastic fluids, especially in applications where precise control of fluid dynamics is required. The insights gained from this study are particularly valuable for improving the analysis of fluid behaviour in medical diagnostics and other related fields.