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Articles 1 - 13 of 13
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A Constrained Adaptive Active Noise Control Filter Design Method Via Online Convex Optimization, Yongjie Zhuang, Yangfan Liu
A Constrained Adaptive Active Noise Control Filter Design Method Via Online Convex Optimization, Yongjie Zhuang, Yangfan Liu
Publications of the Ray W. Herrick Laboratories
In practical active noise control (ANC) applications, various types of constraints may need to be satisfied, e.g., robust stability, disturbance enhancement, and filter output power constraint. Some adaptive filters such as leaky LMS have been developed to apply required constraints indirectly. However, when multiple constraints are required simultaneously, satisfactory noise performance is difficult to achieve by tuning only one leaky factor. Another filter design approach that may achieve better noise control performance is to solve a constrained optimization problem. But the computational complexity of solving such a constrained optimization problem for ANC applications is usually too high even for offline …
A Finite Difference Approach To Study The Impact Of Boundary Conditions On The Acoustical Behavior Of Particle Stacks, Zhuang Mo, Guochenhao Song, Tongyang Shi, J Stuart Bolton
A Finite Difference Approach To Study The Impact Of Boundary Conditions On The Acoustical Behavior Of Particle Stacks, Zhuang Mo, Guochenhao Song, Tongyang Shi, J Stuart Bolton
Publications of the Ray W. Herrick Laboratories
The responses of particle stacks to incident sound waves show interesting features that are very different from those of a homogeneous continuum. Further studies of the acoustical performance of particle stacks can help both to discover potential noise control applications of these types of materials, and to help provide better insight into the internal status of the particle stacks. In the current study, a finite difference (FD) model for a particle stack was built based on the Biot poro-elastic theory. The intention in developing this model is to describe the acoustical behavior of particle stacks with consideration of not only …
Experimental Study And Modeling Of The Level-Dependent Acoustical Behavior Of Granular Particle Stacks, Guochanaho Song, Zhuang Mo, J Stuart Bolton
Experimental Study And Modeling Of The Level-Dependent Acoustical Behavior Of Granular Particle Stacks, Guochanaho Song, Zhuang Mo, J Stuart Bolton
Publications of the Ray W. Herrick Laboratories
Researchers have previously observed elastic modulus softening and increased damping when granular particle stacks are exposed to progressively increasing acoustical excitation levels. However, the level-dependent behavior of granular particle stacks is not well understood, and there are no comprehensive approaches to modeling those effects. Earlier, the authors measured the absorption coefficient of a stack of one type of granular activated carbon stack by using signals having different bandwidths and levels. In the present work, five more types of granular particle stacks were studied to validate and generalize the previous conclusions: i.e., both the modulus softening, and increased damping can be …
A Key Physical Mechanism That Controls The Sound Absorption Of Aerogel Powders, Hasina Begum, Yutong Xue, J Stuart Bolton, Kirill V. Horoshenkov
A Key Physical Mechanism That Controls The Sound Absorption Of Aerogel Powders, Hasina Begum, Yutong Xue, J Stuart Bolton, Kirill V. Horoshenkov
Publications of the Ray W. Herrick Laboratories
A key physical mechanism that controls the acoustic absorption and attenuation in a loose, air-satu-rated aerogel granular mix with the grain diameter being in the order of a few microns is not well understood. A particular challenge here is to understand sound propagation in an aerogel powder composed of highly porous, low-density particles with sub-micron pores. Experimental evidence suggest that a relatively thin layer of an aerogel powder can provide a very high narrow band acoustic absorption at relatively low frequencies. This study presents an attempt to explain this physical phenomenon with two well-known analytical models for the acoustical properties …
A General Stable Approach To Modeling And Coupling Multilayered Systems With Various Types Of Layers, Guochenhao Song, Zhuang Mo, J Stuart Bolton
A General Stable Approach To Modeling And Coupling Multilayered Systems With Various Types Of Layers, Guochenhao Song, Zhuang Mo, J Stuart Bolton
Publications of the Ray W. Herrick Laboratories
In this article, a general method is proposed to model layered systems with two-by-two transfer matrices, and further, to solve for the acoustic absorption, reflection, and transmission coefficients. Since the proposed method uses the matrix representation of various layers and interfaces from the Transfer Matrix Method (TMM), the equation system can be established efficiently. However, the traditional TMM can lose stability when there is a large disparity between the magnitudes of the waves traveling in opposite directions within the layers (i.e., at higher frequencies, for a thick layer, or for extreme parameter values). In such cases, the contribution of the …
Finite Element Modeling Of Force Amplification At The Spindle Due To A Tire’S Cavity Mode: Experimental Verification, Won Hong Choi, Kyosung Choo, J Stuart Bolton
Finite Element Modeling Of Force Amplification At The Spindle Due To A Tire’S Cavity Mode: Experimental Verification, Won Hong Choi, Kyosung Choo, J Stuart Bolton
Publications of the Ray W. Herrick Laboratories
Reduction of tire road noise is an important issue when developing luxury cars and electric vehicles. In this context, the air cavity mode is an important source of spindle forces transmitted to the suspension that then increase interior noise levels. When a tire rotates, the cavity mode near 200 Hz splits into two adjacent modes due to a Doppler effect and tire deformation. That split can lead to increased levels of both longitudinal and vertical spindle forces at the spindle since the two acoustic modes each contribute to both forces when the tire rotates. Thus, it is important to develop …
Diesel Engine Noise Source Visualization By Using Compressive Sensing Algorithms, Tongyang Shi, J Stuart Bolton, Frank Eberhardt
Diesel Engine Noise Source Visualization By Using Compressive Sensing Algorithms, Tongyang Shi, J Stuart Bolton, Frank Eberhardt
Publications of the Ray W. Herrick Laboratories
To identify sound source locations by using Near-field Acoustical Holography (NAH), a large number of microphone measurements is generally required in order to cover the source region and ensure a sufficiently high spatial sampling rate: it may require hundreds of microphones. As a result, such measurements are costly, a fact which has limited the industrial application of NAH to identify sound source locations. However, recently, it has been shown possible to identify concentrated sound sources with a limited number of microphone measurements based on Compressive Sensing theory. In the present work, sound radiation from the front face of a diesel …
The Application Of Tuned Mass Dampers To The Tire Pavement Test Apparatus To Minimize The Impact Of Rig Resonance, Kyosung Choo, J Stuart Bolton, Won Hong Choi, Sangbeom Woo, Matthew Black
The Application Of Tuned Mass Dampers To The Tire Pavement Test Apparatus To Minimize The Impact Of Rig Resonance, Kyosung Choo, J Stuart Bolton, Won Hong Choi, Sangbeom Woo, Matthew Black
Publications of the Ray W. Herrick Laboratories
The ‘Tire Pavement Test Apparatus (TPTA)’ at Purdue University is a device that was originally developed to study a tire’s air-borne noise radiation in the frequency range 300 Hz to 2 kHz. However, in recent years, the device has mainly been used to quantify a tire’s contribution to structure-borne noise by measuring the force and acceleration at the hub. Hence, the frequency range of interest has shifted to frequencies below 300 Hz. By comparing measurements and FE simulations, undesired vibration was observed around 160 Hz in the measurement data. It was speculated that the rig supporting the tire exhibits resonant …
A Finite Difference Approach For Predicting Acoustic Behavior Of The Poro-Elastic Particle Stacks, Zhuang Mo, Guochenhao Song, J Stuart Bolton
A Finite Difference Approach For Predicting Acoustic Behavior Of The Poro-Elastic Particle Stacks, Zhuang Mo, Guochenhao Song, J Stuart Bolton
Publications of the Ray W. Herrick Laboratories
The physical properties of particle stacks have been of interest for a long time, and the acoustic properties of such materials have been actively investigated in recent times. Traditional acoustic theories, such as the Biot theory, can serve as a guide for determining the general properties of the stacks, but they do not allow the identification of the differences between the particle stacks and traditional acoustic materials, which are usually modeled as homogeneous continua. Recent research suggests that the Biot theory, combined with depth-dependent stiffness and equivalent density, can be used to model such materials. In this work, a finite …
Warmstarting The Constrained Optimal Filter Design Problem For Active Noise Control Systems In Conic Formulation, Yongjie Zhuang, Zhuang Mo, Yangfan Liu
Warmstarting The Constrained Optimal Filter Design Problem For Active Noise Control Systems In Conic Formulation, Yongjie Zhuang, Zhuang Mo, Yangfan Liu
Publications of the Ray W. Herrick Laboratories
In practical active noise control (ANC) systems, constraints such as stability, need to be considered in the controller design process. The optimal control filters can be obtained by solving a constrained optimization problem, which requires a significant computational effort. Recently, a convex formulation in conic form was proposed for ANC applications which was shown to result in a computational time reduction by several orders. It is desirable to further improve its efficiency so that the optimal filter design process can be continuously repeated to achieve adaptive control for slow varying operating conditions. One potential way is to introduce a warmstart …
Experimental Study Of The Level-Dependent Softening Of Carbon Particle Stacks, Guochenhao Song, J Stuart Bolton
Experimental Study Of The Level-Dependent Softening Of Carbon Particle Stacks, Guochenhao Song, J Stuart Bolton
Publications of the Ray W. Herrick Laboratories
Recently, it has been observed that a particle stack’s elastic modulus and damping change with incident levels. Hence, the measured normal incidence absorption coefficient also varies: i.e., the quarter-wave resonance peak shifts to a lower frequency and grows broader under progressively higher incident sound levels. Therefore, models with strain-dependent modulus and damping have been developed for sand particles based on a series of cyclic triaxial tests, while more recently, a velocity-dependent modulus was proposed to model the acoustically induced elastic softening for the hollow glass beads. To investigate the nature of this nonlinear behavior, the absorption coefficients of a 30 …
Acoustical Properties Of Granular Aerogel Agglomerates, Amrutha Dasyam, Yutong Xue, Bhisham Sharma, J Stuart Bolton
Acoustical Properties Of Granular Aerogel Agglomerates, Amrutha Dasyam, Yutong Xue, Bhisham Sharma, J Stuart Bolton
Publications of the Ray W. Herrick Laboratories
Granular aerogel agglomerates obtain their unique mechanical and functional properties from their underlying mesoporous structure and intergranular interactions. In this presentation, we focus on the acoustical properties of granular aerogel layers and present experimental results characterizing the absorption behavior of granular silica aerogels with average particle sizes ranging from 5 μm to 2 mm. Our results show that the absorption behavior of granular aerogels strongly depends on the average particle size. To better understand this particle size dependence, we model the granular agglomerates using Biot’s limp and poro-elastic formulation. Finally, we use the developed model to design layered aerogel …
An Iterative Approach For Estimating The Sound Speed And Attenuation Constant Of Air In A Standing Wave Tube, Zhuang Mo, Guochenhao Song, Kang Hou, J Stuart Bolton
An Iterative Approach For Estimating The Sound Speed And Attenuation Constant Of Air In A Standing Wave Tube, Zhuang Mo, Guochenhao Song, Kang Hou, J Stuart Bolton
Publications of the Ray W. Herrick Laboratories
n the present work, an iterative method based on the four-microphone transfer matrix approach was developed for evaluating the sound speed and attenuation constant of air within a standing wave tube. In particular, when the air inside the standing wave tube is treated as the material under test, i.e., as if it were a sample of porous material, the transfer matrix approach can be used to identify the air’s acoustic properties. Note that the wavenumber within the tube is complex owing to the formation of a visco-thermal boundary layer on the inner circumference of the tube. Starting from an assumed …