Research Projects

Transonic flight regimes encountered by both manned and unmanned aerial vehicles (UAVs) are often characterized by shock-induced buffet—a highly unsteady aerodynamic phenomenon resulting from the interaction of shock waves with the boundary layer. This leads to significant fluctuations in aerodynamic loads and pressure fields, which can trigger structural vibrations and degrade flight performance. The issue is further intensified in modern aircraft that rely on lightweight polymer and composite materials, which are more vulnerable to aeroelastic instabilities. These effects are particularly critical during high angle-of-attack maneuvers, where flow separation and shock oscillations become pronounced. While a substantial body of literature exists on shock buffet over airfoils, most studies focus on the suction side near the shock itself, with relatively limited attention given to the buffet-induced wake and its downstream effects. However, experimental and numerical investigations have shown that the turbulent wake shed from the wing can interact strongly with control surfaces such as vertical tails and horizontal tailplanes. These interactions can result in unsteady forces, dynamic loading, and amplified structural response—especially in fighter aircraft with twin-tail configurations and UAVs with compact control architectures. Despite the importance of this issue, there is a lack of comprehensive studies addressing the fluid-structure interaction (FSI) between shock buffet wakes and downstream aerodynamic surfaces. This project aims to fill this gap by developing a high-fidelity aeroelastic simulation and control framework to study and mitigate buffet-induced tailplane instabilities. The methodology begins with 2D simulations of the OAT15A airfoil to validate shock buffet onset and unsteady shock behavior using established benchmarks. Following this, a novel 2D setup involving an airfoil placed in the wake of the OAT15A profile will be used to study buffet transmission and aeroelastic response in a 1-degree-of-freedom (1DOF) structural model. Subsequently, a 3D simulation of a delta wing configuration with twin vertical tails—representative of modern fighter aircraft—will be conducted using fully coupled FSI to evaluate unsteady aerodynamic forces and structural responses in transonic conditions. In the final phase, advanced active control strategies will be explored to mitigate buffet effects using tools from modern control theory and machine learning. These methods aim to suppress unsteady load transmission and improve flight stability, especially in UAVs and next-generation fighter platforms. The expected outcomes include validated FSI models, insights into wake-induced instabilities in tailplanes, and practical control solutions for transonic aeroelastic challenges. These results will directly benefit defense and aerospace agencies such as DRDO and NAL, and contribute to the design of safer, agile, and structurally resilient aircraft.