Development of a Propulsion Rotor Performance Model for Ultra-Low Reynolds Number Flow (Re < 10^5)

A Martian exploration vehicle capable of sustained flight could explore and gather data about large areas of interest from an aerial perspective. NASA has recognized this advantage and has sent Ingenuity — the first helicopter to ever fly in another planet's atmosphere – to Mars, which arrived in February 2021 and is scheduled to fly for the first time in April 2021. The next logical step in progression of vehicle development and testing would be to design and test a fixed-winged drone for Mars exploration. Proving a fixed-winged vehicle could sustain prolonged flight on Mars opens the door to many new avenues of atmospheric planetary exploration. However, flying in the Martian atmosphere – let alone anywhere outside of Earth – has never been attempted before. Fundamental aerodynamic principles related to flight and performance must be reevaluated for Mars atmospheric conditions that have nearly 167x less pressure than Earth's atmospheric pressure at sea level. Reynolds number (Re) – an important aerodynamic characteristic indicative of the nature of the flow field structure and pattern – is the primary metric being examined in this project's analysis for its relationship and effect on propulsion rotor and flight performance. Existing literature has explored the possibility and development of such a propulsion technology, however, no existing public literature has used NASA Ames "Rotor Optimization for the Advancement of Mars eXploration" (ROAMX) team's most recent ultra-low Reynolds number optimized rotor geometry. A Blade Element Momentum Theory analysis code in MATLAB was developed and was verified for its efficacy and accuracy using a reputable external source. For the same rotor geometry and operation conditions, nearly the same outputs were produced compared to the external source's BEMT model. For the five plots used for comparison of model accuracy, the absolute average percent error difference was less than 7.77% at the worst, and 2.11% at best for the data compared. A computational fluid dynamics analysis was performed with ANSYS Fluent on the 7% span location of a ROAMX rotor geometry for discerning 2D blade geometry performance metrics at a Re = 15,000 and Mach number = 0.22. The 7% span location produced relatively low performance coefficients. This was expected, as the 7% span location was optimized for structural rigidity and not aerodynamic performance. The maximum lift to drag ratio was 7.5 at four degrees blade pitch; the maximum lift coefficient was 0.038; and the airfoil appeared to reach the stall condition at eight degrees. Analysis of the 25, 50 and 75-100% blade geometries is expected to yield higher airfoil performance.No embargoAcademic Major: Aerospace Engineerin