One-dimensional unidirectional acoustic boundary through active control method
نویسندگان
چکیده
The unidirectional acoustic boundary has a broad application prospect. Besides the acoustic metamaterial or the strongly nonlinear acoustic medium, which were applied in the realization of the unidirectional acoustic boundary, the present paper proposes another approach through the active control method, where the control source has the property of single directivity. In order to validate its effectiveness in one-dimensional duct, experiment is implemented in two steps: 1. constructing the control source with single directivity by two monopoles; 2. constructing the unidirectional acoustic boundary through the control source in step 1. Results show that the approach to the unidirectional acoustic boundary in one-dimensional duct is feasible and effective, and this work has the potential to be achieved in broadband sound field, in three-dimensional case, and by the adaptive system.
منابع مشابه
Compact and Efficient Active Vibro-acoustic Control of a Smart Plate Structure
An effective wide band active control law through one kind of the Dynamic Vibration Absorber (DVA) is proposed and studied in this paper. With the help of mechanical impedance method, active DVA control law is formulated based on the passive mechanical model. The electrical DVA can generate multi-mode active damping to the structure. The host structure is an aluminum plate and acceleration sign...
متن کاملThree Dimensional Stability Analysis of a Liquid Propellant Combustor
A theoretical study analyzing three-dimensional combustion acoustic instabilities in a liquid propellant rocket engine combustor has been conducted. A linear theory based on Crocco’s pressure sensitive time lag model is used. To apply this theory the combustor is divided into two main components, including the combustion chamber and the converging part of the nozzle. The assumption of concentra...
متن کاملMeasurements of Acoustic Pressure and Velocity Vector in Source Localization using Acoustic Intensity Sensors
Identifying acoustic sources in terms of their relative location is an important factor in active noise control. Traditional source localization measurements uses scalar pressure sensors which proved to be less accurate. Nehorai et al. proposed a different approach for source localization using vector natured acoustic intensity sensors. Four-dimensional (4-D) intensity based algorithm and three...
متن کاملThree-dimensional Vibration Suppression of an Euler-bernolli Beam via Boundary Control Method
In this paper, the general governing equations of three-dimensional vibrations of an Euler-Bernoulli Beam under influences of system dynamics are derived by the Hamiltonian method. Then two fundamental cases of a cantilever beam and a rotating beam are considered. The conventional methods for vibration suppression debit to expenses and make new problems such as control spillover because they ar...
متن کاملActive Noise Control in a Duct With Flow
Active noise control in a one dimensional acoustic duct, in which fluid medium inside the duct has a mean flow velocity, is studied. The acoustic duct model with general boundary conditions is solved in Laplace domain and infinite dimensional system transfer functions are obtained. For controller designs, appropriate microphone, and noise canceling source locations are determined. Low order fin...
متن کامل