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Improved Mars Helicopter Aerodynamic Rotor Model for Comprehensive AnalysesThe Mars Helicopter is part of the NASA Mars 2020 rover mission scheduled to launch in July of 2020. Its goal is to demonstrate the viability and potential of heavier-than-air vehicles in the Martian atmosphere. Ultimately, it aims to bridge the resolution gap between orbiters and the rover as well as allow access to otherwise inaccessible regions. The low density of the Martian atmosphere and the relatively small-scale rotor result in very low Reynolds number flows. The low density and low Reynolds numbers reduce the lifting force and lifting efficiency, respectively. This paper describes the generation of the improved Mars Helicopter aerodynamic rotor model. The goal is to generate a performance model for the Mars Helicopter rotor using a free wake analysis, since this has a low computational cost for design. The improvements in the analysis are two-fold and are expanded on from two prior publications. First, the fidelity of the simulations is increased by performing higher-order two-dimensional time-accurate OVERFLOW simulations allowing for higher accuracy aerodynamic coefficients and a better understanding of the boundary layer behavior as well as its transient features. Second, a version of the model is generated to duplicate the exact testing conditions in the 25-ft. diameter Space Simulator at the Jet Propulsion Laboratory, which allows for better correlation of rotor performance figures. Previous work correlated performance with that test, but did not consider the higher temperatures in the experiment compared to those of the Martian atmosphere. The higher temperatures in the experiment are expected to give conservative performance estimates, as they give rise to an increase in speed of sound and decrease in observed Reynolds numbers.
Document ID
20180006746
Document Type
Conference Paper
Authors
Koning, Witold J. F. (Science and Technology Corp. Hampton, VA, United States)
Johnson, Wayne (NASA Ames Research Center Moffett Field, CA, United States)
Grip, Havard F. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
October 24, 2018
Publication Date
September 18, 2018
Subject Category
Lunar and Planetary Science and Exploration
Aircraft Design, Testing and Performance
Report/Patent Number
ERF Paper No. 2018-28
ARC-E-DAA-TN58739
Meeting Information
European Rotorcraft Forum(Delft)
Funding Number(s)
CONTRACT_GRANT: NNA16BD60C
CONTRACT_GRANT: NNN12AA01C
Distribution Limits
Public
Copyright
Public Use Permitted.
Keywords
Analyses
Rotor Model
Aerodynamic
Improved
Comprehensive
Mars Helicopter

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