Effect of Flexural Rigidity of Dynamically Scaled FW-MAV Wing on Vortex Formation in Low-Re, Unsteady Flow
Abstract
Sub-gram Flapping-Wing Micro-Air Vehicles (FW-MAVs) operate in the regime of Re < 1000 and have unsteady lift generation mechanisms that are sensitive to changes in wing topology. For flapping-and-pitching flyers, the most common micro-robotic wing design is anisotropic and flexible, which can dynamically impact the effective angle of attack. Defined by the dimensionless parameter effective stiffness of the wing, the bending rigidity normalized by the dynamic fluid pressure, this design falls between the fully-rigid and beneficially-flexible regime as defined in current literature. At scale, the aerodynamic force generation has been shown to be highly sensitive to fabrication inconsistencies of the wing and out-of-phase flapping of the wing pair. To isolate the effect of these flexural properties on vortex formation and lift production, we have designed a dynamically-scaled experiment in which only the flap-and-pitch mechanism is submerged in a water tank. The formation and evolution of the wake structure was analyzed with Tomographic-PIV while six-axis F/T data was recorded at the wing root. The effect of the amplitude of the prescribed sinusoidal displacement signals and respective phase lag on force generation and flow characteristics was further investigated.
This work is supported by internal funds at USC.- Publication:
-
APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 2019
- Bibcode:
- 2019APS..DFDB27002S