Computational and Experimental Comparison of CLF5605 and roamx-0201 Martian Helicopter Rotor Airfoils

TL;DR

The paper evaluates two rotor airfoils for Mars: the Ingenuity-era CLF5605 and the optimized roamx-0201, at $Re=20{,}000$ and $Ma=0.60$. Using implicit large-eddy simulations (OVERFLOW), direct numerical simulations (PyFR), and Mars Wind Tunnel experiments, it shows roamx-0201 delivers lower drag for a given lift and achieves up to ~20% higher maximum lift, with improved stall characteristics in 3D-span dynamics. Cross-method comparisons reveal general agreement between OVERFLOW and PyFR, while experimental results highlight manufacturing tolerances and wall/boundary-layer effects as sources of discrepancy. Overall, roamx-0201 demonstrates a strong potential to enhance Mars rotor performance, supporting further rotor-airfoil development for extended range, duration, and payload. This work provides a basis for pursuing roamx-0201-based rotor designs in future Martian missions, potentially enabling broader exploration and science objectives.

Abstract

This study compares aerodynamic performance of the CLF5605 rotor airfoil -- which flew on Ingenuity from 2021 to 2024 -- with that of a new optimized roamx-0201 airfoil designed for Martian conditions at NASA Ames. Specifically, performance is studied at a Reynolds number of 20,000 and a Mach number of 0.60, across a range of angles of attack, using three independent state-of-the-art methodologies: implicit large eddy simulations (ILES) using NASA's OVERFLOW solver, direct numerical simulations (DNS) using the high-order GPU-accelerated PyFR solver, and experimental testing in the Mars Wind Tunnel at Tohoku University. Discrepancies between results obtain using the various methodologies are analyzed and explained. Across all methodologies it can be seen that the roamx-0201 airfoil is able to achieve a given lift with less drag compared to the CLF5605 airfoil. Moreover, OVERFLOW and PyFR results show that the roamx-0201 airfoil has superior stall characteristics, and can achieve a maximum lift ~20% higher than that achieved by the CLF5605 airfoil. The work provides a strong body of evidence to support further studies into use of rotors based on the optimized roamx-0201 airfoil for future Mars helicopter missions.

Figures (45)

• Figure 1: CLF5605 (a) and roamx-0201 (b) airfoils.
• Figure 2: Views of domain and mesh in the streamwise-vertical xy-plane used for 2D simulations with OVERFLOW for the CLF5605 (a) and roamx-0201 (b) airfoils.
• Figure 3: Views of domain and mesh in the streamwise-vertical xy-plane used for 2D and 3D-SP simulations with PyFR for the CLF5605 (a) and roamx-0201 (b) airfoils when $\alpha = 6^{\circ}$.
• Figure 4: View of the computational mesh used for the virtual wind tunnel (VWT) with PyFR for roamx-0201 at $\alpha = 6^{\circ}$. The origin in the streamwise-vertical $xy$-plane is located at the leading edge of the airfoil when $\alpha = 0^{\circ}$.
• Figure 5: The MWT at Tohoku University, Japan. The facility is now located at Nagoya University, Japan.