Micro Aerial Vehicles in Confined Spaces: Are Two Wings Better than One?

Typical missions of micro aerial vehicles include remote sensing tasks in confined spaces, which limit wingspans and restrict maneuvering. Under these conditions, loiter may be limited by reduced endurance brought about by the increased power needs that may accompany wingspan and turning radius restrictions. A theoretical study was therefore performed with the primary purpose to explore aircraft configurations that are more suitable for such constrained flight domains. The theoretical performance model used for this investigation is based on a higher-order potential flow method that uses a table-lookup routine for profile drag prediction and section-lift adjustments for stall prediction. The model considers the increased lift needs during banked flight. Based on this flight performance model, parametric sweeps and multi-parameter gradient-based optimizations were applied to explore those micro aerial vehicle configurations that have minimum power requirements. Typical midspan chord Reynolds numbers ranged from below 100,000 to approximately 400,000. The findings show that, based on a flight mass of 200g, a wingspan of 0.5m, and turning radius restricted to 3.2m, biplane configurations have minimum power requirements that potentially lead to 30% longer endurance than their single-wing counterpart.