The Experts below are selected from a list of 16140 Experts worldwide ranked by ideXlab platform
Xin An Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Sound Absorption Principle of Fibrous Materials
Prespacetime Journal, 2014Co-Authors: Xin An ZhangAbstract:By applying the energy conservation theory and considering the vibration characters of Sound and structure characters of fibrous material, we propose theory and formula for the fibrous material Sound Absorption coefficient and spectrum formula. After analysis and comparison, we find that the theory proposed in the paper is able to correctly reflect the characteristics of the empirical Sound Absorption coefficient laws of fibrous materials found in noise control literature.
-
Elastic Sound Absorption theory of fibrous material
International Journal of Vehicle Noise and Vibration, 2008Co-Authors: Xin An ZhangAbstract:Because of the complexity of classical Sound Absorption theory's expressions, it is difficult to obtain physical insight into the acoustic behaviour of porous materials and to determine the dominant mechanism for Sound Absorption for a given material at a given frequency. Alternatively, there are very simple expressions. A new theory has been put forward that fibrous material absorbs Sound by the fibre's fluctuation. This theory has been justified by the equation obtained from the vibration analysed in this paper as well as the empirical Sound Absorption formula of fibrous material in the author's previous paper.
-
The vibration Sound Absorption theory of soft materials
The Journal of the Acoustical Society of America, 2008Co-Authors: Xin An ZhangAbstract:During the past 2 years, a new theory has been established for soft materials that the vibration of materials brings the Sound Absorption, regardless whether they have pores in them or not. This theory is totally different from Classical theory, such as the Rayleigh model and the Zwikker and Kosten theory. Firstly, an empirical Sound Absorption coefficients formula of fibrous materials was found. Secondly, the theory Sound Absorption formula of thin fiber layers was obtained by the vibration Sound Absorption analysis and the applying of conservation law of energy. This formula agrees well with the empirical Sound Absorption formula of fibrous materials (mentioned above). Based on this achievment and applying classical laws of conservation of momentum and conservation of energy, the Sound Absorption theory formula of membrane (diaphragm) was also obtained, which have been well justified and also agree with the practice. This paper will review and discuss the main point about the vibration Sound Absorption ...
-
The Fiber Vibration Sound Absorption Theory
SAE Technical Paper Series, 2007Co-Authors: Xin An ZhangAbstract:Abstract: Fibrous materials had been used as Sound Absorption materials for over one century .The current Sound Absorption theory is still the Rayleigh model. But this model is just the theory model. It is not agreement with the practice even though it had been studied for over 100 years. Based of this theory, Zwikker and Kosten established the theory of acoustical effective density and the effective bulk modulus which is also the popular theory in acoustics tutorial to explain the Sound Absorption chracteristics of fibrous materials. However, because of the complexity of these expressions, it is difficult to obtain physicalin sight into the acoustic behaviour of the porous materials and to determine the dominant mechanism for Sound Absorption for a given material at a given frequency. Alternatively there are very simple expressions. A new theory was put forward that fibrous material absorb the Sound by the fiber’s vibration . This theory can be proved by the equation obtained by the vibration analyze and also the experimental Sound Absorption formula of fibrous material in another paper of the author.
Mamoru Mabuchi - One of the best experts on this subject based on the ideXlab platform.
-
Sound Absorption characteristics of porous aluminum fabricated by spacer method
Journal of Applied Physics, 2006Co-Authors: Masataka Hakamada, Tetsunume Kuromura, Youqing Chen, Hiromu Kusuda, Mamoru MabuchiAbstract:Porous Al specimens with porosities of 85%–95% and pore sizes of 212–300to610–700μm were fabricated by the spacer method, and their Sound Absorption coefficients were investigated by the transfer function method. The Sound Absorption coefficient increased with porosity. However, there was no apparent correlation between pore size and Sound Absorption coefficient. Also, the Sound Absorption coefficient depended on the thickness. The Sound Absorption coefficient of a specimen was significantly improved by the modification of aperture size, even if the porosity and pore size were unchanged. Therefore, it is suggested that Sound Absorption behavior is strongly affected by not only the porosity and pore size but also the aperture size for porous Al fabricated by the spacer method.
Xu Bo-jun - One of the best experts on this subject based on the ideXlab platform.
-
Simulation of Sound Absorption Model for Dual-Layer Porous Nonwovens
Computer Simulation, 2011Co-Authors: Xu Bo-junAbstract:A theatrical model of Sound Absorption is established for dual-layer porous nonwovens of different types and structures.Based on the variety of the important structural parameters of the nonwoven materials,the effect of the thickness,porosity and pore radius on the Sound Absorption coefficients is explored deeply.With the mathematic model,the relationship between maximum of Sound Absorption coefficient and the structural parameters is researched by simulation,which provides the experimental base for the structure optimization of dual-layer porous Sound Absorption materials.The experiment analysis indicates that the dual-layer porous nonwoven materials have excellent Sound Absorption performance,which provides theory support for the product design.
Masataka Hakamada - One of the best experts on this subject based on the ideXlab platform.
-
Sound Absorption characteristics of porous aluminum fabricated by spacer method
Journal of Applied Physics, 2006Co-Authors: Masataka Hakamada, Tetsunume Kuromura, Youqing Chen, Hiromu Kusuda, Mamoru MabuchiAbstract:Porous Al specimens with porosities of 85%–95% and pore sizes of 212–300to610–700μm were fabricated by the spacer method, and their Sound Absorption coefficients were investigated by the transfer function method. The Sound Absorption coefficient increased with porosity. However, there was no apparent correlation between pore size and Sound Absorption coefficient. Also, the Sound Absorption coefficient depended on the thickness. The Sound Absorption coefficient of a specimen was significantly improved by the modification of aperture size, even if the porosity and pore size were unchanged. Therefore, it is suggested that Sound Absorption behavior is strongly affected by not only the porosity and pore size but also the aperture size for porous Al fabricated by the spacer method.
Tetsunume Kuromura - One of the best experts on this subject based on the ideXlab platform.
-
Sound Absorption characteristics of porous aluminum fabricated by spacer method
Journal of Applied Physics, 2006Co-Authors: Masataka Hakamada, Tetsunume Kuromura, Youqing Chen, Hiromu Kusuda, Mamoru MabuchiAbstract:Porous Al specimens with porosities of 85%–95% and pore sizes of 212–300to610–700μm were fabricated by the spacer method, and their Sound Absorption coefficients were investigated by the transfer function method. The Sound Absorption coefficient increased with porosity. However, there was no apparent correlation between pore size and Sound Absorption coefficient. Also, the Sound Absorption coefficient depended on the thickness. The Sound Absorption coefficient of a specimen was significantly improved by the modification of aperture size, even if the porosity and pore size were unchanged. Therefore, it is suggested that Sound Absorption behavior is strongly affected by not only the porosity and pore size but also the aperture size for porous Al fabricated by the spacer method.