Unsteady penta-hybrid nanofluid blood flow over an oscillating wall with interfacial nanolayer effects: Semi-analytical and statistical study

This study examines unsteady heat and mass transfer in a Casson blood-based suspension flowing past a semi-infinite vertical porous plate under suction, an inclined magnetic field, chemical reaction, and thermal radiation. The suspension is a penta-hybrid nanofluid containing Cu, Fe 3 O 4 , Al 2 O 3 , multi-walled carbon nanotube, and single-layer carbon nanotubes. Interfacial nanolayer effects are used to represent nanoscale particle–fluid interaction and to obtain effective thermophysical properties that enter the macroscopic model. The wall is driven harmonically, and a conjugate heat transfer condition is applied. Similarity variables reduce the equations for momentum, energy, and species to a dimensionless form. Closed-form solutions for temperature and concentration are derived using the Laplace transform with Robin boundary conditions. The velocity field is recovered by numerical inversion of the linear momentum equation. A regression study and sensitivity analysis quantify how key parameters control skin friction, Nusselt number, and Sherwood number. Results show that the penta-hybrid nanofluid enhances wall heat and mass transfer compared with single or binary nanofluids. Magnetic field strength, suction, buoyancy, and reaction rate strongly influence the fields and wall metrics. The analysis links nanoscale composition and nanolayer thickness to vessel-scale transport, which is relevant to bio-thermal management and nanoparticle design in biomedical systems.