共查询到18条相似文献,搜索用时 750 毫秒
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为实现毫米波雷达组件高效可靠的散热,根据前端电讯热控需求,文中提出均温板–翅片一体化风冷热控结构设计方案,并采用仿真设计软件对热设计方案进行了分析和仿真优化。研究结果显示:组件各芯片温度均在安全温度以下,发射芯片的最高结温(最高温度)为141.1?C,与传统风冷散热器相比,采用新型风冷散热器可使芯片最高温度降低9.8?C,强化散热效果明显。此外,也对风冷散热器结构参数和界面接触热阻进行了分析,确定均温板翅片高度30 mm、翅片间距3 mm为该热设计的优选方案。该研究结果可供高效风冷散热和毫米波组件热设计工程应用参考。 相似文献
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穿孔板作为最为常见的消声结构,在各类进、排气系统中均有应用。运用LMS Virtual.lab Acoustics中的有限元分析模块对穿孔板的声学性能进行预测,对穿孔板消声器的设计具有较好的指导作用。研究了不同穿孔率、穿孔孔径以及穿孔壁厚对穿孔板消声器声学性能的影响。通过分析不同结构参数对穿孔板消声器传递损失的影响,得知在中高频段增大穿孔率、穿孔直径以及增加穿孔板壁厚可以增强消声器的消声效果。 相似文献
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In this paper, the sound absorptions of flexible curved micro-perforated panels that are backed by an air cavity are studied in detail. A theoretical model that is based on the classical plate equation coupled with an acoustic wave equation is developed for the prediction of sound absorption. This model considers both symmetrical and antisymmetrical structural acoustic responses. Using the electro-acoustic analogy approach, another model is developed that only considers single structural and acoustic modes. It is proposed to make use of panel and cavity resonances to widen the absorption bandwidth of a single/double perforated absorber. The absorption of a flexible micro-perforated panel can be further enhanced by adjusting its curvature to bring the resonant frequencies closer together. The effects of various parameters such as boundary condition, incidence angle, and curvature on the absorption are studied. Predicted results for the single and double layer absorbers show good agreement with measurements. 相似文献
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Sung-Hee Kim Suk-Yoon Hong Jee-Hun Song Won-Ho Joo 《Journal of Mechanical Science and Technology》2012,26(4):1003-1009
Noise from construction equipment affects not only surrounding residents, but also the operators of the machines. Noise that
affects drivers must be evaluated during the preliminary design stage. This paper suggests an interior noise analysis procedure
for construction equipment cabins. The analysis procedure, which can be used in the preliminary design stage, was investigated
for airborne and structure-borne noise. The total interior noise of a cabin was predicted from the airborne noise analysis
and structure-borne noise analysis. The analysis procedure consists of four steps: modeling, vibration analysis, acoustic
analysis and total interior noise analysis. A mesh model of a cabin for numerical analysis was made at the modeling step.
At the vibration analysis step, the mesh model was verified and modal analysis and frequency response analysis are performed.
At the acoustic analysis step, the vibration results from the vibration analysis step were used as initial values for radiated
noise analysis and noise reduction analysis. Finally, the total cabin interior noise was predicted using the acoustic results
from the acoustic analysis step. Each step was applied to a cabin of a middle-sized excavator and verified by comparison with
measured data. The cabin interior noise of a middle-sized wheel loader and a large-sized forklift were predicted using the
analysis procedure of the four steps and were compared with measured data. The interior noise analysis procedure of construction
equipment cabins is expected to be used during the preliminary design stage. 相似文献
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Min-Chie Chiu Ying-Chun Chang Long-Jyi Yeh Gaung-Jer Lai 《The International Journal of Advanced Manufacturing Technology》2007,32(5-6):537-546
As investigated by the Occupational Safety and Health Act (OSHA) in 1970, noise is highly responsible for the psychological
and physiological illnesses of workers. Therefore, noise control for an enclosed manufacturing system using sound absorbers
becomes indispensable. Considering the minimal acoustic wool used in the high-performance sound absorber during design optimization,
the ratio of the sound absorption coefficient to the thickness of acoustic wool, a cost- and performance-oriented design index,
is then applied and served as a researched objective accordingly; what’s more, the thickness of the absorber is fixed in advance
for the sake of maintenance and access. In this paper, not only is the graphic analysis studied, but also, the computer-aided
numerical assessments are presented. In the computer-graphic analysis on sensitivity, one set of design data is developed
first. Additionally, the successive algorithm of iteration techniques and the original design data are carried out independently.
Moreover, the results are then confirmed by the Kuhn-Tucker condition for accuracy purposes. It is shown that the theoretical
and simulated results are in good agreement. The economical design of the sound absorber proposed in this study definitely
provides a quick and optimal approach to minimize the amount of acoustic wool used and retain the higher acoustic performance
of perforated single-layer absorbers under space restrictions. 相似文献
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影响齿轮箱噪声的因素及其控制方法 总被引:2,自引:0,他引:2
噪声是评价齿轮装置性能的一项重要指标。降低噪声是齿轮箱设计要考虑的主要内容。根据多年从事齿轮箱设计工作的经验,论述影响齿轮箱噪声的因素以及控制与降低噪声的方法。 相似文献
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分别建立某装载机驾驶室及室内声腔有限元模型,通过单点输入多点输出(single input and multiple output,简称SIMO)法模态试验验证了声振耦合模型的准确性,测取悬置点激励进行频率响应分析及室内噪声预测。对驾驶室进行声学灵敏度分析,采用声传递向量法对驾驶室进行声学板件贡献度分析并对关键板件进行形貌优化,同时添加橡胶阻尼材料抑制壁板振动,进行二次声压虚拟预测。结果表明,声学灵敏度分析可得到多阶关键声振耦合频率,声传递向量法板件贡献度分析能准确定位产生噪声峰值的关键板件,形貌优化及添加阻尼材料的方案降噪效果显著,室内总声压级降低了4.43dB。此方案系统地为低噪声车身设计提供了技术路线,减少了传统方案的主观性和重复性,缩短了研发周期,降低了研发成本。 相似文献
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In satellite telecommunications lightweight parabolic reflectors are made with multilayered composite material. During launcher lift-off and the first stage of the flight, vibro-acoustic excitations due to the thrust system and aerodynamic forces are the most critical. The random acoustic load applied to the antenna structure becomes very important and can damage the structure and its equipments. To reduce the acoustic loads, micro-perforated thin shell structures are used in order to reduce the acoustic load applied. CAD and numerical software tools are needed to design and optimise such structures. The computation of the acoustic load induced by a diffuse field on a micro-perforated structure is not classical. The aim of this study is to develop a numerical local impedance model to represent the effect of the perforation to be used within vibro-acoustic software. 相似文献