Zadeh-based fuzzy analysis of carreau tri-hybrid nanofluid hemodynamics in a straight artery with irregular triangular stenosis.

Precise characterization of blood flow in stenosed arteries is crucial for advancing cardiovascular diagnostics and therapeutic interventions. In this study, blood is modeled as a Carreau non-Newtonian fluid flowing through a straight artery with irregular triangular stenosis, capturing realistic geometric complexity. To enhance thermal transport characteristics, three distinct nanoparticles iron oxide (Fe₃O₄), copper (Cu), and gold (Au) are incorporated into the base fluid. A physiologically consistent no-slip boundary condition is imposed along the arterial wall. To address inherent uncertainties in rheological and physical parameters, the model is developed within a fuzzy framework using Zadeh's extension principle. The governing continuity, momentum, and energy equations are transformed into their weak formulation and solved numerically using the Fuzzy Finite Element Method (FFEM). The influence of Carreau fluid parameters on velocity, pressure distribution, and temperature fields is systematically investigated. The results demonstrate notable thermal enhancement due to the tri-hybrid nanoparticle suspension, while the fuzzy analysis ensures bounded uncertainty and improved robustness of the predictions. The proposed framework offers a reliable and comprehensive approach for analyzing complex arterial hemodynamics, with potential relevance for uncertainty-aware cardiovascular and thermal transport analysis.