The Directionality of Blade-vortex Interaction Noise PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download The Directionality of Blade-vortex Interaction Noise PDF full book. Access full book title The Directionality of Blade-vortex Interaction Noise by Todd Darwin Ringler. Download full books in PDF and EPUB format.
Author: Todd Darwin Ringler
Publisher:
ISBN:
Category :
Languages : en
Pages : 332
Get Book Here
Book Description
Author: Todd Darwin Ringler
Publisher:
ISBN:
Category :
Languages : en
Pages : 332
Get Book Here
Book Description
Author: Wel-Chong Sim
Publisher:
ISBN:
Category :
Languages : en
Pages : 360
Get Book Here
Book Description
Author: Fredric H. Schmitz
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: National Aeronautics and Space Adm Nasa
Publisher:
ISBN: 9781728917214
Category :
Languages : en
Pages : 28
Get Book Here
Book Description
Acoustic measurements from a model rotor wind tunnel test are presented which show that the directionality of rotor blade vortex interaction (BVI) noise is strongly dependent on the rotor advance ratio and disk attitude. A rotor free wake analysis is used to show that the general locus of interactions on the rotor disk is also strongly dependent on advance ratio and disk attitude. A comparison of the changing directionality of the BVI noise with changes in the interaction locations shows that the strongest noise radiation occurs in the direction of motion normal to the blade span at the time of interaction, for both advancing and retreating side BVI. For advancing side interactions, the BVI radiation angle down from the tip-path plane appears relatively insensitive to rotor operating condition and is typically between 40 and 55 deg below the disk. However, the azimuthal radiation direction shows a clear trend with descent speed, moving towards the right of the flight path with increasing descent speed. The movement of the strongest radiation direction is attributed to the movement of the interaction locations on the rotor disk with increasing descent speed. Martin, R. M. and Marcolini, Michael A. and Splettstoesser, W. R. and Schultz, K.-J. Langley Research Center RTOP 505-63-51-06...
Author: Ruth McVoy Martin
Publisher:
ISBN:
Category : Rotors (Helicopters)
Languages : en
Pages : 32
Get Book Here
Book Description
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722428778
Category :
Languages : en
Pages : 60
Get Book Here
Book Description
A comparison of experimental acoustics data and computational predictions was performed for a helicopter rotor blade interacting with a parallel vortex. The experiment was designed to examine the aerodynamics and acoustics of parallel Blade-Vortex Interaction (BVI) and was performed in the Ames Research Center (ARC) 80- by 120-Foot Subsonic Wind Tunnel. An independently generated vortex interacted with a small-scale, nonlifting helicopter rotor at the 180 deg azimuth angle to create the interaction in a controlled environment. Computational Fluid Dynamics (CFD) was used to calculate near-field pressure time histories. The CFD code, called Transonic Unsteady Rotor Navier-Stokes (TURNS), was used to make comparisons with the acoustic pressure measurement at two microphone locations and several test conditions. The test conditions examined included hover tip Mach numbers of 0.6 and 0.7, advance ratio of 0.2, positive and negative vortex rotation, and the vortex passing above and below the rotor blade by 0.25 rotor chords. The results show that the CFD qualitatively predicts the acoustic characteristics very well, but quantitatively overpredicts the peak-to-peak sound pressure level by 15 percent in most cases. There also exists a discrepancy in the phasing (about 4 deg) of the BVI event in some cases. Additional calculations were performed to examine the effects of vortex strength, thickness, time accuracy, and directionality. This study validates the TURNS code for prediction of near-field acoustic pressures of controlled parallel BVI. McCluer, Megan S. Ames Research Center...
Author: See-Ho Wong
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Ruth McVoy Martin
Publisher:
ISBN:
Category : Acoustical engineering
Languages : en
Pages : 48
Get Book Here
Book Description
Author: M. C. Joshi
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Acoustical engineering
Languages : en
Pages : 48
Get Book Here
Book Description
