Recent NASA Wind Tunnel Free-Flight Testing Of A Multirotor Unmanned Aircraft System

Miller, Luke J.; Busan, Ronald C.; Langston, Sarah; Hartman, David

doi:10.2514/6.2020-1504

Cited by 5 publications

(3 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[19] investigates hexacopters in tractor and pusher configurations at different airspeeds and pitch angles. In [20] the authors conduct free flight wind tunnel tests inside NASA's 12-foot low speed tunnel and their 20-foot vertical spin tunnel.…”

Section: B Suas Wind Tunnel Testingmentioning

confidence: 99%

Wind Tunnel Testing and Aerodynamic Characterization of a QuadPlane Uncrewed Aircraft System

Mathur¹,

Atkins²

2023

Preprint

View full text Add to dashboard Cite

Electric Vertical Takeoff and Landing (eVTOL) vehicles will open new opportunities in aviation. This paper describes the design and wind tunnel analysis of an eVTOL uncrewed aircraft system (UAS) prototype with a traditional aircraft wing, tail, and puller motor along with four vertical thrust pusher motors. Vehicle design and construction are summarized. Dynamic thrust from propulsion modules is experimentally determined at different airspeeds over a large sweep of propeller angles of attack. Wind tunnel tests with the vehicle prototype cover a suite of hover, transition and cruise flight conditions. Net aerodynamic forces and moments are distinctly computed and compared for plane, quadrotor and hybrid flight modes. Coefficient-based models are developed. Polynomial curve fits accurately capture observed data over all test configurations. To our knowledge, the presented wind tunnel experimental analysis for a multi-mode eVTOL platform is novel. Increased drag and reduced dynamic thrust likely due to flow interactions will be important to address in future designs.

show abstract

Section: B Suas Wind Tunnel Testingmentioning

confidence: 99%

Wind Tunnel Testing and Aerodynamic Characterization of a QuadPlane Uncrewed Aircraft System

Mathur¹,

Atkins²

2023

Preprint

View full text Add to dashboard Cite

show abstract

“…Russell et al [1,2] completed such an experiment using several multi-rotor vehicles of varying sizes, and Baris et al [3] also conducted a separate experiment with the DJI Phantom 3 Advanced quadrotor. Foster et al [4] developed a system with tethers for their wind tunnel experiment to carry out free-flight testing of a quadrotor and determine the trim conditions in straight level flight as well as vertically descending flight at different speeds.…”

Section: Introductionmentioning

confidence: 99%

A Study on Circulation Strength Decay Over Time of Quadrotor Wake Using Large Eddy Simulation

Nathanael

Wang

Low

2022

AIAA SCITECH 2022 Forum

View full text Add to dashboard Cite

As the use of multi-rotors is becoming common, understanding how the wake vortices develop and decay from a multi-rotor is important to reduce the effect of wake vortices on other multi-rotors and ensure their safety during operation by applying a wake separation minima. This paper proposes a method of flow simulation in ANSYS Fluent to study the decay of wake vortices from quadrotor propellers as the vortices evolve over distance and time. First, the near-field wake flow from the quadrotor propellers was simulated using Reynolds-Averaged Navier-Stokes (RANS) turbulence model. The velocity profile in the quadrotor frame of reference was then extracted to be applied for a flow simulation using Large Eddy Simulation (LES). The circulation strength as a function of distance could then be calculated, but it was limited by the length of the computational grid due to the wake flow being seen from the quadrotor frame of reference. To change into the stationary frame of reference, the interpolation data from the first stage LES was exported and modified by subtracting the freestream velocity from the velocity component in the freestream direction. The modified interpolation data was then used for the second stage LES, and the circulation strength in terms of time could be calculated from the resulting wake flow. Three cases of flow simulation are presented in this paper: first using 380-mm-diameter propellers based on the SUI Endurance quadrotor propellers with forward flight speed of 6 m/s, second using the 380-mm-diameter propellers with 12 m/s speed, and third using 240-mm-diameter propellers (similar to the propellers of DJI Phantom quadrotor) with 12 m/s speed. Findings regarding the decay of wake vortex from multi-rotor vehicles will help in determining the safe separation distance required to mitigate the hazards due to wake vortex encounters and ensure the safety of multi-rotor vehicles.

show abstract

“…The main limitation of the aforementioned studies is they consider multicopters mounted in custom test stands so that only hover flight conditions are investigated. To this end, in 2019 NASA Langley Research Center [12] leveraged a vertical wind tunnel to evaluate the dynamic response of small commercial multirotor UAS. Free flight conditions were simulated in the 12-foot Low Speed Tunnel as well as in the 20-foot Vertical Speed Tunnel designing a tethered system to prevent damages in case of loss of control or during failure analysis.…”

Section: Introductionmentioning

confidence: 99%

Unmanned Aircraft Systems Performance in a Climate-Controlled Laboratory

Scanavino

Avi

Vilardi

et al. 2021

J Intell Robot Syst

View full text Add to dashboard Cite

Despite many research studies focus on strategies to improve autopilot capabilities and bring artificial intelligence onboard Unmanned Aircraft Systems (UAS), there are still few experimental activities related to these vehicle performance under unconventional weather conditions. Air temperature and altitudes directly affect thrust and power coefficients of small scale propeller for UAS applications. Reynolds numbers are usually within the range 10,000 to 100,000 and important aerodynamic effects, such as the laminar separation bubbles, occur with a negative impact on propulsion performance. The development of autonomous UAS platforms to reduce pilot work-load and allow Beyond Visual Line of Sight (BVLOS) operations requires experimental data to validate capabilities of these innovative vehicles. High quality data are needed for a deep understanding of limitations and opportunities of UAS under unconventional flight conditions. The primary objective of this article is to present the characterization of a propeller and a quadrotor capabilities in a pressure-climate-controlled chamber. Mechanical and electrical data are measured with a dedicated test setup over a wide range of temperatures and altitudes. Test results are presented in terms of thrust and power coefficient trends. The experimental data shows low Reynolds numbers are responsible for degraded thrust performance. Moreover, details on brushless motor capabilities are also discussed considering different temperature and pressure conditions. The experimental data collected in the test campaign will be leveraged to improve UAS design, propulsion system modelling as well as to provide guidelines for safe UAS operations in extreme environments.

show abstract

Recent NASA Wind Tunnel Free-Flight Testing Of A Multirotor Unmanned Aircraft System

Cited by 5 publications

References 5 publications

Wind Tunnel Testing and Aerodynamic Characterization of a QuadPlane Uncrewed Aircraft System

Wind Tunnel Testing and Aerodynamic Characterization of a QuadPlane Uncrewed Aircraft System

A Study on Circulation Strength Decay Over Time of Quadrotor Wake Using Large Eddy Simulation

Unmanned Aircraft Systems Performance in a Climate-Controlled Laboratory

Contact Info

Product

Resources

About