Influence of peristaltic flow on double‐diffusive convection through a porous medium in an annulus

In the current study, we have examined the effects of double‐diffusive mixed convection between two vertical concentric uniform tubes of an incompressible viscous peristaltic flow in a porous medium. The outer tube has a sinusoidal waveform, while the inner tube is taken as uniform and rigid. We have considered the wave frame of orientation with the small Reynolds number and temperature‐dependent heat sink parameter by using the wavelength approximation. The closed‐form solutions of governing equations have been obtained for the temperature, concentration, axial pressure gradient, axial velocity, as well as stream function in terms of Bessel's function, containing some parameters related to this model. The pressure rise has been examined by using numerical integration. The impact of different emerging physical constants on the flow characteristics is deliberated by the graphs in detail. Results show that the axial pressure gradient decreases with an increase in the dimensionless mean flow rate, Darcy number, Schmidt number, chemical reaction parameter, and heat sink parameter, while it rises with higher thermal and solutal Grashof numbers. The pressure difference initially decreases within certain flow rate ranges but rises beyond these intervals. Additionally, temperature and concentration profiles rise with the amplitude, temperature, and radius ratios, while isotherm intensity decreases with a stronger heat sink effect. The fluid exhibits rigid, block‐like behavior at large heat sink values, and the trapped bolus size expands with increasing Grashof numbers due to temperature and concentration. These findings have practical applications in biomedical engineering, such as modeling blood flow in arteries, gastrointestinal peristalsis, endoscopic techniques, dialysis systems, and drug delivery mechanisms. Moreover, they are relevant in industrial processes, including peristaltic pumping of slurries, enhanced oil recovery, thermal management in porous heat exchangers, microfluidic devices, and chemical reactors, where efficient heat and mass transfer are critical.