- Physical Review Journals
All JournalsPhysics Magazine
Access Provided by Xinjiang University

Physical Review Fluids

Export citation

Export citation

Choose format for download:

Download Citation
  • Editors' Suggestion
  • Access by Xinjiang University

Experimental and numerical investigations on rotor noise in axial descending flight

Yuhong Li, Xiangtian Li, Han Wu, Peng Zhou, and Xin Zhang*

Siyang Zhong†

  • Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region of China

  • Department of Aeronautical and Aviation Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region of China

  • *aexzhang@ust.hk
  • †siyang.zhong@polyu.edu.hk
PDF

Phys. Rev. Fluids 8, 094803 – Published 28 September, 2023

DOI: https://doi.org/10.1103/PhysRevFluids.8.094803

Abstract

While various aerodynamic noise generation mechanisms and characteristics have been extensively studied for drone research, the noise features during the descending flight state have not been well addressed. In this work, we investigate the aerodynamics and aeroacoustics of a two-bladed drone rotor operating in descent using both experimental and numerical approaches. First, we measure the rotor thrust and torque in an anechoic wind tunnel at various rotational speeds and descent rates. The results reveal a significant loss of mean thrust and strong thrust fluctuations with the increase of descent rates due to the formation of highly unsteady vortex rings. The measured acoustic spectra show multiple humps occurring at the blade passing frequency and its harmonics. Next, we perform numerical simulations based on the delayed detached eddy simulations to gain more understanding of the noise generation mechanisms. The computed integrated aerodynamic forces and acoustic spectra agree well with the experimental results. We present nearfield flow structures that demonstrate the gradual formation process of the vortex ring and the complex turbulent wake structures. Notably, the computed aeroacoustic characteristics exhibit a similar tendency with respect to the descent rate to the experimental results. Moreover, the simulation results suggest that the additional noise has a radiation directivity in the axial direction perpendicular to the rotation plane. Finally, we conduct a noise source analysis on the blade surface based on the simulation results, revealing that the strong leading-edge sources are likely related to the blade-wake interaction process during descending flight.

View figure in article

Physics Subject Headings (PhySH)

Article Text

References (54)

  1. D. Floreano and R. J. Wood, Science, technology and the future of small autonomous drones, Nature 521, 460 (2015).
  2. S. Rajendran and S. Srinivas, Air taxi service for urban mobility: A critical review of recent developments, future challenges, and opportunities, Transport. Res. Part E: Logist. Transport. Rev. 143, 102090 (2020).
  3. A. Straubinger, R. Rothfeld, M. Shamiyeh, K. D. Büchter, J. Kaiser, and K. O. Plötner, An overview of current research and developments in urban air mobility—Setting the scene for UAM introduction, J. Air Transp. Manage. 87, 101852 (2020).
  4. S. A. Rizzi, D. L. Huff, D. D. Boyd, P. Bent, R. Boeing, S. Louis, B. S. Henderson, R. Snider, B. Flight, and F. Worth, Urban air mobility noise: Current practice, gaps, and recommendations, NASA/TP-2020-5007433 (2020), https://ntrs.nasa.gov/citations/20205007433.
  5. S. Zhong, P. Zhou, R. Fattah, and X. Zhang, A revisit of the tonal noise of small rotors, Proc. R. Soc. A 476, 20200491 (2020).
  6. J. Wu, H. Jiang, Z. Ma, W. Chen, and X. Huang, Numerical investigation of airfoil-rotor interaction at low Reynolds number, Phys. Fluids 34, 025118 (2022).
  7. G. Romani, E. Grande, F. Avallone, D. Ragni, and D. Casalino, Computational study of flow incidence effects on the aeroacoustics of low blade-tip Mach number propellers, Aerosp. Sci. Technol. 120, 107275 (2022).
  8. R. R. Mankbadi, S. O. Afari, and V. V. Golubev, High-fidelity simulations of noise generation in a propeller-driven unmanned aerial vehicle, AIAA J. 59, 1020 (2021).
  9. R. Gojon, T. Jardin, and H. Parisot-Dupuis, Experimental investigation of low Reynolds number rotor noise, J. Acoust. Soc. Am. 149, 3813 (2021).
  10. H. Hu, Y. Yang, Y. Liu, X. Liu, and Y. Wang, Aerodynamic and aeroacoustic investigations of multi-copter rotors with leading edge serrations during forward flight, Aerosp. Sci. Technol. 112, 106669 (2021).
  11. H. Jiang, H. Wu, W. Chen, P. Zhou, S. Zhong, X. Zhang, G. Zhou, and B. Chen, Toward high-efficiency low-noise propellers: A numerical and experimental study, Phys. Fluids 34, 076116 (2022).
  12. S. Glegg and W. Devenport, Aeroacoustics of Low Mach Number Flows Fundamentals, Analysis, and Measurement (Academic Press, San Diego, CA, 2017), pp. 3–8.
  13. Gutin, On the sound field of a rotating propeller, NACA-TM-1995 (1948), https://ntrs.nasa.gov/citations/20030068996.
  14. C. Morfey, Rotating blades and aerodynamic sound, J. Sound Vib. 28, 587 (1973).
  15. D. B. Hanson, Near-field frequency-domain theory for propeller noise, AIAA J. 23, 499 (1985).
  16. Y. H. Yu, Rotor blade-vortex interaction noise, Prog. Aerosp. Sci. 36, 97 (2000).
  17. Y. Wu, M. J. Kingan, and S. T. Go, Propeller-strut interaction tone noise, Phys. Fluids 34, 055116 (2022).
  18. S. Zhong, P. Zhou, W. Chen, H. Jiang, H. Wu, and X. Zhang, An investigation of rotor aeroacoustics with unsteady motions and uncertainty factors, J. Fluid Mech. 956, A16 (2023).
  19. Y. Li, H. Wu, H. Jiang, S. Zhong, and X. Zhang, Computational aeroacoustics study of propellers with vibrational motion, AIAA J. 61, 3091 (2023).
  20. R. K. Amiet, Noise produced by turbulent flow into a propeller or helicopter rotor, AIAA J. 15, 307 (1977).
  21. R. H. Schlinker and R. K. Amiet, Helicopter rotor trailing edge noise, NASA-CR-3470 (1981), https://doi.org/10.2514/6.1981-2001.
  22. T. Brooks, D. Pope, and M. Marcolini, Airfoil self-noise and prediction, NASA-RP-1218 (1989), https://ntrs.nasa.gov/citations/19890016302.
  23. Y. Yang, Y. Liu, Y. Li, E. Arcondoulis, and Y. Wang, Aerodynamic and aeroacoustic performance of an isolated multicopter rotor during forward flight, AIAA J. 58, 1171 (2020).
  24. Y. Yauwenas, J. Fischer, D. Moreau, and C. Doolan, The effect of inflow disturbance on drone propeller noise, in 25th AIAA/CEAS Aeroacoustics Conference, AIAA Paper 2019-2633 (2019), https://doi.org/10.2514/6.2019-2663.
  25. H. Wu, W. Chen, H. Jiang, S. Zhong, and X. Zhang, Experimental investigation of the effect of sectional airfoil profile deviation on propeller noise, Phys. Fluids 35, 027104 (2023).
  26. D. Casalino, E. Grande, G. Romani, D. Ragni, and F. Avallone, Definition of a benchmark for low Reynolds number propeller aeroacoustics, Aerosp. Sci. Technol. 113, 106707 (2021).
  27. C. Nardari, D. Casalino, F. Polidoro, V. Coralic, P.-T. Lew, and J. Brodie, Numerical and experimental investigation of flow confinement effects on UAV rotor noise, AIAA Paper 2019-2497 (2019), https://doi.org/10.2514/6.2019-2497.
  28. H. Lee and D. J. Lee, Rotor interactional effects on aerodynamic and noise characteristics of a small multirotor unmanned aerial vehicle, Phys. Fluids 32, 047107 (2020).
  29. N. S. Zawodny and D. D. Boyd, Investigation of rotor-airframe interaction noise associated with small-scale rotary-wing unmanned aircraft systems, J. Am. Helicopter Soc. 65, 1 (2020).
  30. J. Stack, F. X. Caradonna, and Ö. Savaş, Flow visualizations and extended thrust time histories of rotor vortex wakes in descent, J. Am. Helicopt. Soc. 50, 279 (2005).
  31. J. Seddon and S. Newman, Basic Helicopter Aerodynamics (John Wiley & Sons, New York, 2011), Chap. 2, pp. 23–61.
  32. A. Brand, M. Dreier, R. Kisor, and T. Wood, The nature of vortex ring state, J. Am. Helicopt. Soc. 56, 22001 (2011).
  33. J. G. Leishman, M. J. Bhagwat, and S. Ananthan, The vortex ring state as a spatially and temporally developing wake instability, J. Am. Helicopt. Soc. 49, 160 (2004).
  34. O. Shetty and M. Selig, Small-scale propellers operating in the vortex ring state, in 49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, AIAA Paper 2011-1254 (2011), https://doi.org/10.2514/6.2011-1254.
  35. M. P. Kinzel, J. K. Cornelius, S. Schmitz, J. L. Palacios, J. W. Langelaan, D. Adams, and R. Lorenz, An investigation of the behavior of a coaxial rotor in descent and ground effect, in AIAA Scitech 2019 Forum, AIAA Paper 2019-1098 (2019), https://doi.org/10.2514/6.2019-1098.
  36. G. Throneberry, A. Takeshita, C. M. Hocut, F. Shu, and A. Abdelkefi, Multi-rotor wake characterization and visualization in ascending and descending flight, Exp. Fluids 63, 98 (2022).
  37. S. Chae, S. Lee, and J. Kim, Effects of rotor-rotor interaction on the wake characteristics of twin rotors in axial descent, J. Fluid Mech. 952, A31 (2022).
  38. M. Veismann, Effects of rotor separation on the axial descent performance of dual-rotor configurations, Flow 3, E7 (2023).
  39. M. Veismann, D. Yos, and M. Gharib, Parametric study of small-scale rotors in axial descent, Phys. Fluids 34, 035124 (2022).
  40. P. Spalart, S. Deck, M. Shur, K. Squires, M. Strelets, and A. Travin, A new version of detached-eddy simulation, resistant to ambiguous grid densities, Theor. Comput. Fluid Dyn. 20, 181 (2006).
  41. W. Yi, P. Zhou, Y. Fang, J. Guo, S. Zhong, X. Zhang, X. Huang, G. Zhou, and B. Chen, Design and characterization of a multifunctional low-speed anechoic wind tunnel at HKUST, Aerosp. Sci. Technol. 115, 106814 (2021).
  42. H. Jiang and X. Zhang, An acoustic-wave preserved artificial compressibility method for low-Mach-number aeroacoustic simulations, J. Sound Vib. 516, 116505 (2022).
  43. P. Spalart and S. Allmaras, A one-equation turbulence model for aerodynamic flows, in 30th Aerospace Sciences Meeting and Exhibit, AIAA Paper 1992-439 (1992), https://doi.org/10.2514/6.1992-439.
  44. J. E. Ffowcs-Williams and D. L. Hawkings, Sound generation by turbulence and surfaces in arbitrary motion, Philos. Trans. R. Soc. Lond. Ser. A 264, 321 (1969).
  45. F. Farassat, Derivation of formulations 1 and 1A of Farassat, NASA/TM-2007-214853 (2007), https://ntrs.nasa.gov/citations/20070010579.
  46. P. Welch, The use of fast Fourier transform for the estimation of power spectra: A method based on time averaging over short, modified periodograms, IEEE Trans. Audio Electroacoust. 15, 70 (1967).
  47. R. Hogg, J. McKean, and A. Craig, Introduction to Mathematical Statistics (Pearson Education, Boston, 2005).
  48. G. T. Chapman, Topological classification of flow separation on three-dimensional bodies, in 24th Aerospace Sciences Meeting, AIAA Paper 1986-0485 (1986), https://doi.org/10.2514/6.1986-485.
  49. J. H. Stephenson, D. Weitsman, and N. S. Zawodny, Effects of flow recirculation on unmanned aircraft system (UAS) acoustic measurements in closed anechoic chambers, J. Acoust. Soc. Am. 145, 1153 (2019).
  50. H. H. Murray, W. J. Devenport, W. N. Alexander, S. A. L. Glegg, and D. Wisda, Aeroacoustics of a rotor ingesting a planar boundary layer at high thrust, J. Fluid Mech. 850, 212 (2018).
  51. S. H. Wasala, R. C. Storey, S. E. Norris, and J. E. Cater, Aeroacoustic noise prediction for wind turbines using large eddy simulation, J. Wind Eng. Ind. Aerodynam. 145, 17 (2015).
  52. X. Tan, Z. Yang, X. Tan, X. Wu, and J. Zhang, Vortex structures and aeroacoustic performance of the flow field of the pantograph, J. Sound Vib. 432, 17 (2018).
  53. J. Yangzhou, J. Wu, Z. Ma, and X. Huang, Aeroacoustic sources analysis of wake-ingesting propeller noise, J. Fluid Mech. 962, A29 (2023).
  54. N. S. Zawodny, D. B. Jr., and C. L. Burley, Acoustic characterization and prediction of representative, small-scale rotary-wing unmmaned aircraft system components, NASA TR NF1676L-22587 (2016), https://ntrs.nasa.gov/citations/20160009054.

Outline

Information

Phys. Rev. Fluids 8, 094803– Published 28 September, 2023
  • Received 18 May 2023
  • Accepted 18 August 2023
Crossmark - Check for updates button

©2023 American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation