Date of Award

2019

Document Type

Thesis

Degree Name

Master of Science in Engineering (MSE)

Department

Mechanical and Aerospace Engineering

Committee Chair

Chang-kwon Kang

Committee Member

David Brian Landrum

Committee Member

Farbod Fahimi

Subject(s)

Wings (Anatomy)--Aerodynamics, Space vehicles--Aerodynamics, Mars (Planet)--Atmospheric density

Abstract

A Mars flight vehicle could provide a third-dimension for ground-based rovers and supplement orbital observation stations, providing a much more detailed aerial view of the landscape as well as unprecedented survey of the atmosphere of Mars. However, flight on Mars is a difficult proposition . Due to very low atmospheric density, approximately 1.3% of sea level density on Earth, aircraft must fly approximately ten times faster, or be one hundred times Iighter in weight than their Earth counterparts, to lift themselves on Mars. While traditional aircraft efficiency suffers in the low Reynolds number environment, flapping wing insect inspired flyers on Mars might be able to take advantage of the same lift enhancing effects as insects on Earth. In this thesis, the feasibility of using a bioinspired, flapping wing flight vehicle to produce lift in an ultralow- density Martian atmosphere is investigated. A four-wing prototype, inspired by a prior study, with a single wingspan of 12 cm with an area of 0.0070 m2 was placed in an atmospheric chamber to simulate Martian density. The peak-to-peak flapping amplitude was 35 deg for the upper wings and 30 deg for the lower wings, with flapping frequencies ranging from 5 to 18 Hz. Lift was measured by an ATI Nano-17 force transducer. Wing deformation was simultaneously tracked using a Vicon motion capture system. In Earth density conditions, the passive pitch wing deflection increased monotonically with flapping frequency. Conversely, in the Martian density environment, the passive pitch deflection angles did not follow a consistent pattern, sometimes even deflecting in the direction opposite of expected. When in the Martian density environment, the lift generated by the flapper was measured to be an order of magnitude greater than the inertial forces generated by the flapping motion. The lift generally increased with flapping frequency. However, when the flapping frequency was 14 Hz and between 17 and 19 Hz, the wing passive pitch angles were suboptimal. Nevertheless, the measured lift peaked at around 8 grams at 16 Hz. These measurements suggest that sufficient aerodynamic forces for hover on Mars can be generated for a 6-gram flapping wing vehicle.

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