From Empirical to Predictive: Advancing Active Flow Control through Numerical Modeling and Synthetic Jet Actuation

Fluid flow control has become an area of significant focus within the research community. Historically, the design of flow control strategies has relied heavily on trial-and-error methods, guided by the experience and intuition of engineers. However, such approaches are increasingly inadequate in meeting the growing demands for higher-quality designs within shorter development cycles. This article aims to demonstrate the effectiveness and reliability of Computational Fluid Dynamics (CFD) in elevating flow control from an empirical practice to a predictive and science-based discipline. The rapid advancements in CFD capabilities -driven by improvements in computational power and data storage- have been instrumental in addressing complex flow control challenges. To support this objective, the article begins by briefly outlining fundamental fluid flow problems, followed by a detailed examination of flow separation phenomena in selected cases. Key concepts in flow control are presented, with a particular focus on active control of boundary layer separation over aerodynamic surfaces. The implementation of control mechanisms within CFD simulations is discussed, including guidance on the appropriate specification of boundary conditions. These discussions are supplemented with notable and foundational applications to underscore the practical significance of CFD in flow control analysis. Additionally, various modeling approaches for airflow are explored in depth to provide a robust engineering framework for solving control-related problems. The examples presented in this article have been carefully chosen to highlight the versatility and applicability of CFD techniques across multiple engineering domains.