Domain Overlapping Semi‐Analytic Solutions of Unsteady Stagnation Hybrid SWCNT–Titania Nanofluids With Entropy Production Over an Exponentially Stretched Disk

ABSTRACT This study highlights the analysis of unsteady stagnation hybrid SWCNT–titania nanofluids with water as a base fluid, and entropy production over an exponentially stretched disk. The spectral local linearization method (SLLM) extended with an overlapping‐grid multi‐domain Chebyshev scheme is employed numerically. The study reveals reversal impacts of the time parameter on the velocity ratio (reduction/increment) for values less/greater than 1. Higher volume fractions lead to higher resistance, heat transfer, and nanoparticle dispersion. Thermal radiation and Prandtl number progress the heat transfer with adverse impacts of Brinkman number and time parameter. The results show the significant influence of the Prandtl number and radiation parameter on the temperature distribution, emphasizing their critical role in governing thermal behavior. It has been observed that hybrid nanofluid outperforms single nanofluids in terms of heat transfer rate. Additionally, results reveal that the efficiency of heat transport varies with time. The mass transfer is always improved by surging Brownian motion parameter and Lewis number. Entropy analysis reveals that characteristic time ratio, time parameter, far‐field velocity ratio, thermal radiation, Brownian motion, and thermophoresis are essential for optimizing nanofluid applications. The study highlights the significance of considering time scales associated with viscous diffusion and convective transport. The findings underscore the practical relevance of hybrid nanofluids in heat exchangers, electronic cooling, and other industrial applications where efficient heat transfer and thermal regulation are essential.