Noise of counter-rotation propellers

Hanson, D. B.

doi:10.2514/3.45173

Cited by 129 publications

(62 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These aerodynamic interactions consist mainly in the mutual effects of each rotor potential field, in the cutting of the front rotor viscous wake by the rear rotor blades, and in the cutting of the front rotor tip vortices by the rear rotor blades. These aerodynamic interaction sources are responsible for unsteady pressure fluctuations on the blades that will radiate noise with directivities depending on front and rear rotor blade counts, rotation speed, flight Mach number, and blade geometries coupled with the intensity and phasing of the aerodynamic interactions seen by both rotors [4].…”

Section: Introductionmentioning

confidence: 99%

Influence of Torque Ratio on Counter-Rotating Open-Rotor Interaction Noise

Delattre

Falissard

2015

AIAA Journal

View full text Add to dashboard Cite

This paper investigates the influence of the torque ratio, at constant total thrust, on the interaction noise of a generic counter-rotating open rotor in pusher configuration. It is shown that torque ratio has a small influence on the openrotor aerodynamic performance but a strong impact on interaction noise at takeoff condition. The noise source mechanisms are investigated in detail and linked with the characteristics of the front rotor blade-tip vortices. Tip vortex characteristics are detailed and compared with analytical vortex models. It is verified that torque ratio variation has no strong impact on the open-rotor aerodynamic performance at cruise condition.

show abstract

Section: Introductionmentioning

confidence: 99%

Influence of Torque Ratio on Counter-Rotating Open-Rotor Interaction Noise

Delattre

Falissard

2015

AIAA Journal

View full text Add to dashboard Cite

show abstract

“…The first technique that considers counter-rotating dipoles is the semi-analytical model proposed by Hanson. 16 It predicts the far-field acoustic pressure p(x,r,θ) for any CROR using the dipole source distribution over the blades. For the rear rotor ( R 2 ), it reads in the time domain: where …”

Section: Computational Approachmentioning

confidence: 99%

Numerical assessment of the tonal noise of Counter-Rotating Open Rotors at approach

Soulat

Kernemp

Sanjosé

et al. 2016

International Journal of Aeroacoustics

View full text Add to dashboard Cite

A hybrid method combining a three-dimensional unsteady Reynolds-Averaged Navier–Stokes simulation of a cropped Counter-Rotating Open Rotors at approach conditions and an acoustic analogy either based on a time formulation, an advanced-time formulation of Ffowcs-Williams and Hawkings’ analogy, or on a frequency formulation, an extension of Hanson’s model to non compact chord length, has shown three main sources, the impacts of the front-rotor wakes on the aft-rotor, of the front-rotor tip vortex on the aft-rotor tip, and of the front-rotor hub horse-shoe vortex on the aft-rotor blade foot. Consequently, this study confirms that the aft-rotor is the dominant tonal noise source and has identified another potential noise source when the Counter-Rotating Open Rotors is installed caused by the strong tip vortex of the highly loaded cropped aft-rotor. The present rotor–rotor distance should not be reduced as the potential effect from the aft rotor is already felt on the front rotor. The influence of several numerical parameters including grid refinement, data sampling, and simulation length has been evaluated on both aerodynamic and acoustic performances.

show abstract

“…The noise spectrum from the NASA ORPR with F31/A31 blades has been analyzed by Elliott [14], and is known to have substantial number of interaction tones. These are caused by aerodynamic interactions, categorized by Hanson as viscous wakes, shed potential wakes, and bound potential effects [15]. It is readily expected that the aft rotor will generate noise due to all three of these effects.…”

Section: Figure 7 Effect Of Aft Rotor Phase On Inter-rotor Velocity mentioning

confidence: 99%

Effect of Aft Rotor on the Inter-Rotor Flow of an Open Rotor Propulsion System

Slaboch

Stephens

Zante

et al. 2016

Journal of Engineering for Gas Turbines and Power

View full text Add to dashboard Cite

The effects of the aft rotor on the inter-rotor flow field of an open rotor propulsion rig were examined. A Particle Image Velocimetry (PIV) dataset that was acquired phase locked to the front rotor position has been phase averaged based on the relative phase angle between the forward and aft rotors. The aft rotor phase was determined by feature tracking in raw PIV images through an image processing algorithm. The effects of the aft rotor potential field on the inter-rotor flow were analyzed and shown to be in reasonably good agreement with Computational Fluid Dynamics (CFD) simulations. The aft rotor position was shown to have a significant upstream effect, with implications for front rotor interaction noise. It was found that the aft rotor had no substantial effect on the position of the forward rotor tip vortex but did have a small effect on the circulation strength of the vortex when the rotors were highly loaded.

show abstract

Noise of counter-rotation propellers

Cited by 129 publications

References 7 publications

Influence of Torque Ratio on Counter-Rotating Open-Rotor Interaction Noise

Influence of Torque Ratio on Counter-Rotating Open-Rotor Interaction Noise

Numerical assessment of the tonal noise of Counter-Rotating Open Rotors at approach

Effect of Aft Rotor on the Inter-Rotor Flow of an Open Rotor Propulsion System

Contact Info

Product

Resources

About