Análise numérica da perda de carga em escoamento de fluido de lei de potência em uma válvula de gaveta 50% aberta

Abstract

Non-Newtonian fluids exhibit distinct viscous behaviors. Among rheological models, the Power Law provides one of the simplest representations for describing dilatant and pseudoplastic fluids,requiring studies to understand their flow. In industrial systems, gate valves are widely used for flow control, but when partially open, they can induce cavitation and significant pressure losses. The determination of the pressure loss coefficient for these fluids depends on both the system’s geometry and their rheological properties, making its estimation a challenge. In this context, computational simulation emerges as an effective tool for analyzing flow behavior and calculating pressure gradients, enabling a better understanding of the effects of fluid properties. Thus, the objective of this study is to perform a numerical simulation of the flow of a power-law fluid through a gate valve with a partial opening of 50%. For this, the commercial software Ansys Fluent® was used to analyze the influence of flow parameters (velocity, power-law index, and consistency index) and to propose an empirical correlation for the pressure loss coefficient in this configuration. The main results obtained show that an increase in the consistency and power-law indices directly influences the rise in fluid viscosity, offering greater resistance to flow and resulting in higher pressure losses. This effect is amplified when the flow is subjected to higher velocities. Furthermore, the empirical correlation between the resistance coefficient and the Reynolds number revealed an inverse relationship between these two factors, where fluids with higher Reynolds numbers tend to exhibit less viscous flows, leading to lower pressure losses.