Stenosis effects on Jeffrey fluid flow in two-layer microcirculatory models: a physicochemical and hemorheological analysis

Blood is a multifaceted colloidal suspension of plasma as an aqueous electrolyte-protein fluid and cellular components, mainly red blood cells, the rheology of which is influenced by mutually reinforcing hydrodynamic and chemical interactions, such as protein-mediated aggregation, plasma composition, and solute transport. These physicochemical interactions are magnified in stenosed micro vessels resulting in great changes in effective viscosity and haematocrit distribution. The present study develops a theoretical two-layer model in order to explain the synergistic action of stenosis and microcirculation on Jeffrey fluid dynamics. The middle region is modelled as a viscoelastic Jeffrey fluid, which considers the red blood cell elasticity and shear-thinning effect, and the outer layer as a Newtonian plasma. The governing equations are analytically solved with slip boundary conditions and mild stenosis with analytic expressions of velocity profiles, flow flux, effective viscosity, core haematocrit, and mean haematocrit. The findings indicate that an effective viscosity is positively proportional to stenosis height, channel half-width and slip parameter and negatively related to the Jeffrey parameter, and thus, the interplay between the viscous recovery of red blood cells and the breakup of plasma-protein networks induced by shear is demonstrated. Moreover, core and mean haematocrit drop off with a growing degree of stenosis and slip, as predicted by the Fahraeus-Lindqvist effect and the law of colloidal segregation. The suggested framework combines rheological modelling and chemical understanding connecting the flow changes caused by stenosis with the transport of solutes, reaction-diffusion dynamics, and drug and nanoparticle delivery efficacy, which provides a chemically informed view of hemorheology with potential biomedical chemistry, pharmaceutical formulation, and clinical diagnostics applications.