Estimation of Optimal Acoustic Liner Impedance Factor for Reduction of Radiated Engine Noise
نویسندگان
چکیده
We study the optimal design problem of acoustic liner to minimize fan noise radiation from commercial aircraft engine nacelles. Specifically we treat the liner impedance factor as a parameter and seek to estimate its optimal value that minimizes far-field radiated noise. The existence of such an optimal parameter is proved under the assumption that the Helmholtz equation governs the noise field. We also present numerical results to demonstrate that the choice of the optimal liner impedance factor does result in significant reduction of noise level in the far-field.
منابع مشابه
Numerical Solutions for Optimal Control Problems under Spde Constraints
The primary source of aircraft noise is the fan noise from the engines; natural approaches to reducing this noise involve acoustic shape optimization of the inlet and impedance optimization of the liner. This project will use optimal control to systematically determine the inlet shape and the linear material impedance factor that minimize the fan noise. A novel feature of this approach is that ...
متن کاملNumerical Optimization of Radiated Engine Noise with Uncertain Wavenumbers
The purpose of this paper is to study the optimal design of the acoustic liner to minimize fan noise radiation from commercial aircraft engine nacelles. There have been numerous studies of this problem from an engineering perspective (e.g., [12, 26, 27] and references therein). In [8, 11], the search for the liner material minimizing engine noise radiation was treated as an optimal control prob...
متن کاملExperimental Evaluation of Acoustic Engine Liner Models Developed with COMSOL Multiphysics
Accurate modeling tools are needed to design new engine liners capable of reducing aircraft noise. The purpose of this study is to determine if a commercially-available finite element package, COMSOL Multiphysics, can be used to accurately model a range of different acoustic engine liner designs, and in the process, collect and document a benchmark dataset that can be used in both current and f...
متن کاملAn Optimal Shape Design Problem for Fan Noise Reduction
Noise generated by the rotating blades of an aircraft turbofan engines continues to pose a challenge for many researchers and of course, the reduction of the noise have been received more attention in the recent studies. Williams and Hall studied aerodynamic sound generation by turbulent flow around a scattering half plane [1]. Howe in [2] discussed the trailing edge noise at low Mach numbers. ...
متن کاملOn enhanced sound absorption by non-uniform liners
ABSTRACT The use of acoustic liners is a common means of noise reduction in jet engine exhausts. The quest for more effective sound absorption mechanisms in cylindrical ducts has led to the consideration of non-uniform liners, with impedance varying circumferentially, axially, or in both directions. The present paper is based on the theory of mode coupling in a non-uniformly lined cylindrical d...
متن کامل