In this research, novel model-free method based on machine learning for closed-loop control of flow separation behind a step is introduced. The primary goal of this study is to reduce the recirculation zone behind the step at a Reynolds number of 1350, which is achieved by a jet slot. In this study, the flow was simulated as steady and two-dimensional based on finite volume discretization. Feedback control rules have been optimized based on a cost function that includes the area of the recirculation flow and the costs associated with the injection. This optimization process was carried out using genetic programming algorithms. A tree-based genetic programming was used to construct various injection model functions and create a closed-loop control system. After evolving through 8 generations with 500 samples in each generation, the algorithm arrives at a feedback rule capable of reducing the recirculation flow area by up to 60%. This machine learning-based control system was compared with the best open-loop jet based on Kelvin-Helmholtz frequency pulsation.
Kasmaiee, S., Tadjfar, M. & kasmaiee, S. (2025). Optimal Closed-Loop Control of Step Flow Separation Using Genetic Programming. Journal Of Applied and Computational Sciences in Mechanics, 37(3), 1–26. https://doi.org/10.22067/jacsm.2024.88143.1261
MLA
Kasmaiee, S., Tadjfar, M., & kasmaiee, S. "Optimal Closed-Loop Control of Step Flow Separation Using Genetic Programming", Journal Of Applied and Computational Sciences in Mechanics, 37, 3, 2025, 1–26. doi: 10.22067/jacsm.2024.88143.1261
HARVARD
Kasmaiee, S., Tadjfar, M., & kasmaiee, S. (2025). 'Optimal Closed-Loop Control of Step Flow Separation Using Genetic Programming', Journal Of Applied and Computational Sciences in Mechanics, 37(3), pp. 1–26. doi: 10.22067/jacsm.2024.88143.1261
CHICAGO
Kasmaiee, S., Tadjfar, M. & kasmaiee, S., "Optimal Closed-Loop Control of Step Flow Separation Using Genetic Programming." Journal Of Applied and Computational Sciences in Mechanics, 37 3 (2025): 1–26, doi: 10.22067/jacsm.2024.88143.1261
VANCOUVER
Kasmaiee S., Tadjfar M., kasmaiee S. Optimal Closed-Loop Control of Step Flow Separation Using Genetic Programming. FUM-MECH. 2025;37(3):1–26 (In Persian). doi: 10.22067/jacsm.2024.88143.1261