Aircraft noise

About: Aircraft noise is a research topic. Over the lifetime, 3051 publications have been published within this topic receiving 32039 citations.

Interim prediction method for turbine noise

Abstract: A turbine noise prediction method for interim use in the NASA Aircraft Noise Prediction Program is selected The method predicts the level, directivity, and one-third octave band spectra of far field turbine noise as a function of engine parameters The selection results from a review of turbine noise data and prediction methods available in the open literature It is concluded that the state-of-the-art turbine noise prediction capability is primitive and that the selected method represents only a temporary interim approach Recommendations are made on research requirements

Large-eddy-simulation prediction of an installed jet flow and noise with experimental validation

Abstract: Extra noise is generated when jets are installed beneath solid surface. In this paper, large-eddy simulation (LES) has been used to investigate these jet installation effects. The simulations were ...

Evaluation of an Aircraft Concept With Over-Wing, Hydrogen-Fueled Engines for Reduced Noise and Emissions

Abstract: This report describes the analytical modeling and evaluation of an unconventional commercial transport aircraft concept designed to address aircraft noise and emission issues. A strut-braced wing configuration with overwing, ultra-high bypass ratio, hydrogen fueled turbofan engines is considered. Estimated noise and emission characteristics are compared to a conventional configuration designed for the same mission and significant benefits are identified. The design challenges and technology issues which would have to be addressed to make the concept a viable alternative to current aircraft designs are discussed. This concept is one of the "Quiet Green Transport" aircraft concepts studied as part of NASA's Revolutionary Aerospace Systems Concepts (RASC) Program. The RASC Program seeks to develop revolutionary concepts that address strategic objectives of the NASA Enterprises, such as reducing aircraft noise and emissions, and to identify enabling advanced technology requirements for the concepts.

On the Development of Semi-Empirical Noise Models for the Prediction of the Noise from Jets with Forced Mixers

Abstract: In recent years there has been a significant interest in the development of jet noise prediction models due to increased restrictions on aircraft noise near airports. However, currently there are no industry tools that can be used to predict the noise from the complex flows of modern jet engines that include internal forced mixers. The four-source method is a noise prediction tool applicable to simple coplanar, coaxial jets. In this study the fundamental components of the four-source model are used as the building blocks for a noise prediction method which would be applicable to coaxial jets with internal forced mixers. First, the four-source model is applied to an internally mixed jet with a confluent or axisymmetric mixer. A two-source noise model is then proposed to predict the noise for cases with an internal forced mixer. Three variable parameters in this two-source model are optimized to match the forced mixer experimental noise data. It is shown that the twosource noise model is capable of accurately modeling the noise spectra of internally mixed jets with forced mixers.