Design construtal de bifurcações em forma de Y para escoamentos de fluidos de Carreau

Abstract

This work investigates the optimal geometries for bifurcations subject to pseudoplastic non-Newtonian fluid flows, and to analyze how the fluid rheology has effects on the configurations and performance of Y-shaped bifurcations. The analysis is based on minimization flow resistance, with the definition of the ratio of diameters, length ratio and bifurcation angle as degrees of freedom and design parameters and imposition of restrictions according to the Design Constructal method. The fluid was modeled using the Carreau equation, and the effects of Carreau number, viscosity ratio and flow index were analyzed. The flows were solved numerically using the Finite Volume Method and the ANSYS® Fluent software. The mathematical model was verified with results published in the literature, and the computational mesh was analyzed by the GCI method. The Response Surface optimization algorithm was used to search for the minimum flow resistance and the optimal values for the design variables. A three-level factorial design was used to verify the effect of the rheological parameters on these results. From the results obtained, it was found that the power index is the rheological parameter that has the greatest effect on the configuration of the optimal geometry, affecting both the length ratio and the ratio of diameters to the minimum flow resistance. statistically significant effect was only on the ratio of diameters. This, in turn, proved to be the geometric parameter that had the greatest influence on the flow resistance behavior. These results corroborate the thesis that the analysis for systems with non-Newtonian fluids should consider the rheology of fluids to obtain their best performance.