A Prediction Procedure for Propeller Aircraft Flyover Noise Based on Empirical Data

Smith, Michael H.

doi:10.4271/810604

Cited by 5 publications

(2 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All these models are based on approximate equations involving, among the most important parameters, rotor power, RPM, number of blades, flight speed, and rotor diameter. Among the earliest empirical methods based on approximated equations is the one introduced by Smith [7], who proposed an empirical model developed using a regression test analysis from A-weighted sound level data obtained during certification tests of single and twin engines airplanes. In his contribution, Smith included, in addition to the aforementioned model parameters, also blade tip twist and blade thickness, accounting respectively for more correct spanwise loading distributions and thickness noise estimation, the latter being particularly important for high tip speed propellers.…”

Section: Introductionmentioning

confidence: 99%

Towards a Fast Non-Empiric Source Model for Installed Rotor Noise

Franco

Ewert

Moessner

et al. 2021

Aiaa Aviation 2021 Forum

View full text Add to dashboard Cite

The recent demand for sustainable aviation designs challenges aircraft manufacturers to reconsider existing technologies in light of the required cuts in environmental pollution. One of the key factors in addressing these green targets is represented by the integration of unconventional propulsion concepts on the airframe, exploiting electrically driven designs. Among the necessary targets to achieve, a substantial noise emission reduction is needed. Since the new aircraft designs could include existing or novel propulsion system components to address the challenge of reliably predicting noise emissions, in this work a simplified, fast and physicalprinciples-based rotor noise model is introduced, together with suitable adapted perturbation equations to represent current and possibly newly arising noise sources mechanisms. The rotor noise model is based on rotating point or line sources that represent loading noise in terms of equivalent body forces. The model is applied in a Computational Aeroacoustics (CAA) framework in the time domain. The Linearized Euler Equations (LEE) are split into two separate perturbation equation systems for the acoustic and vorticity mode, respectively. The new noise prediction model, together with the new equations, are implemented in the unstructured quadrature-free experimental Discontinuous Galerkin (DG) CAA solver DISCO++ of DLR. Acoustic Perturbation Equations (APE) describe the propagation of the acoustic mode, and can be discretized numerically very robustly in the DG-framework. The equation splitup intends to overcome numerical stability issues present in the discretization of the LEE with the DG method. The paper reports initial successful results and outlines future possible applications.

show abstract

Section: Introductionmentioning

confidence: 99%

Towards a Fast Non-Empiric Source Model for Installed Rotor Noise

Franco

Ewert

Moessner

et al. 2021

Aiaa Aviation 2021 Forum

View full text Add to dashboard Cite

show abstract

“…In terms of noise predictions, empirical methods with non-linear corrections are still utilised today. Such empirical models include those described by Magliozzi [7], Smith [8] and Dobrzynski [9]. Although such models can be deemed to provide accurate solutions, the dominating non-linearity associated with a multi-rotor eVTOL design requires higher-fidelity methods, such as Navier-Stokes based fluid dynamics.…”

Section: Introductionmentioning

confidence: 99%

A computational fluid dynamic acoustic investigation of a tiltwing eVTOL concept aircraft

Higgins

Barakos

Shahpar

et al. 2021

Aerospace Science and Technology

View full text Add to dashboard Cite

Predicting the effect of electric and hybrid-electric aviation on acoustic pollution

et al. 2020

View full text Add to dashboard Cite

In the quest for the reduction of noise pollution, novel hybrid-electric or fully-electric power-trains promise to provide a substantial contribution. Especially closer to airfields, where acceptability issues tend to limit air operations with conventional fuel-burning engines, such novel power-trains allow to fly terminal maneuvers with a dramatically reduced impact on pollution. Considering the General Aviation (GA) field, where such new types of propulsion are more likely to gain a significant market share thanks to their favorable characteristics for this weight category, the reduction of the noise impact on ground may increase the infrastructural value of smaller airfields, often located in densely populated areas. This in turn would help in making novel power-train technologies economically advantageous at a system level. Despite these evident advantages, a methodology to quantify noise emissions of a novel type of power-train has not been identified yet – a fundamental step towards the assessment of the potential contribution of hybrid-electric or fully-electric aircraft to the global scenario of future aviation. This work introduces and discusses a possible procedure to provide such estimation. While mainly focused on the field of propeller-driven GA aircraft, the procedure presented herein can be easily scaled to cope with the specific features of heavier categories.

show abstract

A Prediction Procedure for Propeller Aircraft Flyover Noise Based on Empirical Data

Cited by 5 publications

References 4 publications

Towards a Fast Non-Empiric Source Model for Installed Rotor Noise

Towards a Fast Non-Empiric Source Model for Installed Rotor Noise

A computational fluid dynamic acoustic investigation of a tiltwing eVTOL concept aircraft

Predicting the effect of electric and hybrid-electric aviation on acoustic pollution

Contact Info

Product

Resources

About