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- Real-time optimization of wing drag and lift performance using a movable leading edgePublication . Camacho, E. A. R.; Silva, Maíra Martins da; Silva, A. R. R.; Marques, Flávio D.A real-time optimization strategy can provide any system with a considerable boost in performance on the fly, which in real-world applications can be translated to lower energy consumption or higher efficiency. This study investigates the particular case of using real-time optimization to improve wing aerodynamic performance with a dynamically activated deflectable leading edge. Its activation aims to minimize drag and maximize lift and is governed by real-time and gradient-based optimization. An extension to a classic method is suggested to enhance gradient estimation accuracy. Experimental data are obtained at a Reynolds number of with the wing fixed at five positions. For each of these positions, optimal leading-edge deflections are found. The results indicate that deflecting the leading edge has a negligible impact on drag and lift before the stall onset. However, the reduction in the pitching moment cannot be ignored. When the wing is experiencing a proper stall, the movable leading edge yields remarkable enhancements, with the lift being approximately raised by 45% together with a substantial increase in the critical angle of attack. The findings highlight the potential of real-time optimization in experimental aerodynamic studies, reinvigorating its application in improving aircraft performance.
- Thrust force assessment of a MFC-actuated tail-like robotic fish using Unsteady Panel MethodPublication . Silva, Maíra Martins da ; Camacho, Emanuel António Rodrigues ; Silva, André Resende Rodrigues da ; Marques, Flávio D.Fish-like robots are used in various fields, such as environmental monitoring and underwater exploration. These devices are designed to emulate the motion of a real fish. They can have flexible bodies to mimic body/caudal-based locomotion patterns or fins to mimic median/paired fin-based locomotion patterns. Standard propulsion methods include oscillating fins, flapping tails, and body undulations. This work investigates a robotic fish with a flexible tail actuated by a Macro-Fiber Composite (MFC) pair in a bi-morph configuration. This device is designed to mimic body/caudal-based locomotion patterns; therefore, it should present propulsion capabilities due to its body undulations. These propulsion capabilities are assessed using the Unsteady Panel Method for different sinusoidal inputs. This method requires the device’s kinematics, which is derived using an analytical model based on the Euler–Bernoulli beam theory, considering the electro-mechanical coupling of the actuators. The mean thrust force derived using the Unsteady Panel Method is compared with the actual mean thrust acquired during an experimental campaign. The experimental and numerical results indicated that higher thrust forces can be achieved when the device is excited in its second resonance frequency. These results are in line with Lighthill’s findings.