|
|
|
|
|
Qun Yan, Dongwen Xue, Qinqin Mu, Jiafeng Yang, Xiang Gao and Wenchao Huang
An aircraft nacelle acoustic liner is a key mean of aircraft noise reduction. The success of its design depends strongly on the development of experimental technology, which is generally divided into two stages: impedance eduction and the modal verificat...
ver más
|
|
|
|
|
|
|
|
|
|
|
Moritz Neubauer, Julia Genßler, Vincent Radmann, Fleming Kohlenberg, Michael Pohl, Kurt Böhme, Karsten Knobloch, Ennes Sarradj, Klaus Höschler, Niels Modler and Lars Enghardt
This paper presents a combined experimental and numerical investigation on a novel liner concept for enhanced low-frequency and broadband acoustic attenuation. In particular, two different realizations, derived from conventional Helmholtz resonators (HR)...
ver más
|
|
|
|
|
|
|
|
|
|
|
Abhishek Gautam, Alper Celik and Mahdi Azarpeyvand
The use of acoustic liners, based on double-degree-of-freedom Helmholtz resonators, for low-frequency-noise attenuation is limited by the volume of individual resonating cavities. This study investigates the effect of the septum neck length on the acoust...
ver más
|
|
|
|
|
|
|
|
|
|
|
Constantin Sandu, Andrei-George Totu, Andrei-Tudor Trifu and Marius Deaconu
This paper presents the technological advancement of using friction powders to increase the absorption of acoustic liners used in the reduction of tonal noise generated by aero-engines or for other applications related to Helmholtz resonators used in noi...
ver más
|
|
|
|
|
|
|
|
|
|
|
Vadim Palchikovskiy, Aleksandr Kuznetsov, Igor Khramtsov and Oleg Kustov
A comparison is considered of the experimentally obtained impedance of locally reacting acoustic liner samples with the impedance calculated using semi-empirical Goodrich, Sobolev and Eversman models. The semi-empirical impedance models are outlined. In ...
ver más
|
|
|
|
|
|
|
|
|
|
|
Giorgio Palma, Lorenzo Burghignoli, Francesco Centracchio and Umberto Iemma
Modern turbofans with high bypass ratios, low blade passage frequencies and short nacelles require continuous development of acoustic linings to achieve the noise reductions expected by the international aviation authorities. Metamaterials and metafluids...
ver más
|
|
|
|
|
|