Effect of non-equilibrium aggregation of nanoparticles on heat and mass transport and sensitivity in nanofluid flow during blood circulation

This paper examines the impact of non-equilibrium particle aggregation on heat and mass transport and sensitivity issues in nanofluids during blood flow. The study first establishes the heat and mass transfer control equations for the flow system. Using a similarity transformation, the complex system of partial differential equations is reduced to a set of ordinary differential equations, which are then solved using the fourth-order Runge–Kutta method to collect data. Using the friction coefficient (Cf) and the thermal transfer efficiency (Nu) as core evaluation metrics, quantify the friction resistance and thermal-mass transfer performance of nanofluids. Further regression analysis was conducted using the response surface methodology (RSM), establishing a quadratic regression function with particle volume fraction, particle aggregation evolution time, and magnetic field parameters as input variables, and Cf and Nu as dependent variables. This clearly revealed the coupled influence patterns of the three factors on friction drag and heat and mass transfer performance. The results indicate that in the A–B interaction, when A=B=1, the Nusselt number resides within the locally optimal range. Concurrently, the sensitivity analysis clarified the sensitivity of Cf and Nu to the three control factors. This study presents quantitative methods and key references for optimizing parameters in nanofluid friction resistance and heat and mass transfer systems.