Results 11 to 20 of about 94,319 (292)
Shielding of rotor noise by plates and wings
Acta Acustica, 2022 A method of noise reduction proposed for the next generation of aircraft is to shield noise from the propulsion system, by positioning the noise source over a wing or another surface.
Carley Michael
doaj +1 more source
Machines, 2022 In this paper, we designed flat conductor winding permanent magnet synchronous motors with three different rotor structures under certain boundary conditions.
Kai Zhao, Jian Luo
doaj +1 more source
A revisit of the tonal noise of small rotors [PDF]
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2020 In this study, asymptotic analysis of the frequency-domain formulation to compute the tonal noise of the small rotors in the now ubiquitously multi-rotor powered drones is conducted. Simple scaling laws are proposed to evaluate the impacts of the influential parameters such as blade number, flow speed, rotation speed, unsteady motion, thrust and ...
Siyang Zhong +3 more
openaire +4 more sources
Nonharmonic Control of the Blade-Vortex Interaction Noise of Electrically Controlled Rotor
International Journal of Aerospace Engineering, 2022 Electrically controlled rotor, also known as swashplateless rotor, represents an active rotor system that, due to the use of a trailing edge flap system instead of a swashplate, not only enables primary control but also conveniently reduces the blade ...
Kewei Li +3 more
doaj +1 more source
Aerospace, 2022 The accurate prediction of helicopter rotor blade–vortex interaction (BVI) noise is challenging. This paper presents an implementation of the seventh-order improved weighted essentially non-oscillatory (WENO-Z) scheme for predicting rotor BVI noise using
Yan Sun, Yongjie Shi, Guohua Xu
doaj +1 more source
Hydrodynamic Effect of Highly Skewed Horizontal-Axis Tidal Turbine (HATT) Rotors
Energies, 2023 While hydro turbines generate over 40% of the world’s total renewable energy, these traditional turbines present a great environmental concern due to the potential of their sharp blades to damage aquatic lives and ecology, along with their harmful noise ...
Yiyi Xu, Juin Ming Foong, Pengfei Liu
doaj +1 more source
Machines, 2023 Research on helicopter transient maneuvering flight noise is a hotspot and challenging topic in the fields of helicopter design and application. A new time-accurate free-wake (TAFW) method and the Fowcs Williams-Hawkings (FW–H) equations are applied to ...
Zhiyuan Hu +3 more
doaj +1 more source
International Journal of Aerospace Engineering, 2022 This paper presents a numerical investigation of unsteady surface blowing using periodic variations of jet velocity with azimuthal angle to reduce helicopter rotor blade-vortex interaction (BVI) noise.
Yan Sun, Guohua Xu, Yongjie Shi
doaj +1 more source
Experimental Analysis of Rotor Blade Noise in Edgewise Turbulence
Aerospace, 2023 This paper presents an experimental investigation into the effects of turbulence ingestion on the aerodynamic noise characteristics of rotor blades in edgewise flight. A small-scaled, two-bladed rotor was used in the study.
Nur Syafiqah Jamaluddin +4 more
doaj +1 more source
Fluid-Dynamic and Aeroacoustic Characterization of Side-by-Side Rotor Interaction
Aerospace, 2023 An investigation of twin corotating rotors’ interaction effects was performed by load (thrust and torque) measurements, flow field dynamics through Time-Resolved Particle Image Velocimetry, and acoustic emissions using a microphone array.
Ranieri Emanuele Nargi +4 more
doaj +1 more source