Fully Coupled DNS Simulation of Flow Separation Control over MAV with Flexible Lifting Surfaces

Micro Air Vehicles (MAVs) are being considered for a wide range of roles from search-and-rescue in urban environments, military surveillance and reconnaissance, to planetary exploration. To accomplish these complex missions, a good understanding of complex flow physics involved in the flow separation and transition around the flexible lifting surface of MAV is crucial. In Phase I, an in-house, advanced simulation tool with coupled fluid-structure interaction, moving and deforming grid and high-fidelity Direct Numerical Simulation (DNS) capability will be leveraged and demonstrated. The adapted tool will be able to accurately capture the strong coupling of structure dynamics of flexible lifting surface and the surrounding flow, and to predict the flow behavior of unsteady aerodynamics, including boundary layer separation, lift and drag, turbulence transition from low to transition Reynolds number range flights, and the stress and structural deformation of the flexible wing of MAV. High-fidelity simulation of MAV with flexible deforming lifting surfaces under condition of potential resonance of first few structure modes will be carried out using first principle based DNS. In Phase II, the developed model will be used to conduct investigation of the flow physics of flexible lifting surfaces and to study various means of controlling the flow separation. This simulation environment will ultimately lead to the development of a comprehensive stability and control model for practical MAVs. BENEFIT: A capability to accurately predict and control the flow separation over a flexible lift surface of MAV can lead to many potential commercial applications of MAV. The designed MAV can be used in an urban warfare environment to conduct reconnaissance in areas not accessible to larger aircraft, such as areas within buildings, to identify and segregate military targets versus areas having high civilian concentrations. It can also be used in environmental monitoring, traffic monitoring, counter-drug operations, accident assessment, and wildlife/land management. Other applications include inspecting high monuments, monitoring risk of first fires, or more generally for interventions in narrow and hazardous environments, where it would be dangerous to send a human agent.