Scenario-based Range and Mission Optimization Harnessing Mutual Aerodynamic Interaction Between Multiple Aircraft

Favorable aerodynamic interference in formation flight can be used to lower the overall induced drag and extend the range of a group of aircraft. The overall fuel consumption of a good formation arrangement is significantly less than the total fuel consumption when each aircraft flies in isolation. However, the benefits of the drag reduction are not necessarily equally divided among the individual aircraft, which means that some aircraft have higher fuel consumption than others. Longitudinal separation determines how the overall drag benefit is divided among the individual aircraft. For a formation to have nearly equal drag benefits among the individuals, small longitudinal separation is necessary, which increases the risk of collision. We propose reconfigurable formation geometries in which the inter-aircraft separation is altered to suit the mission and the situation. By tailoring formation configurations to suit the situation, it is possible to enable missions involving disparate aircraft having different fuel states. The proposed research effort will result in fast aerodynamic analysis methods that are validated with more computationally expensive, higher-fidelity methods. These analysis techniques will be used to calculate the time-varying fuel consumption of different aircraft in a formation. Together, these methods will be used for situation-dependent rapid formation-geometry optimization and estimation of the mission range for different scenarios.