共查询到19条相似文献,搜索用时 265 毫秒
1.
2.
3.
4.
5.
基于LabView的多功能声级计设计 总被引:2,自引:0,他引:2
在常规的噪声测量中普遍采用声级计,传统的声级计一般是利用硬件计权网络实现对噪声信号的计权,利用硬件的滤波网络实现噪声的倍频程分析以及给出平均声级等。设计了一种基于LabView的虚拟式声级计,介绍了该虚拟声级计的硬件结构、软件设计流程、频率计权和统计分析模块。采用TES-1356音压校准器对所设计的系统进行了校准,通过和TES-1357精密声级计的比较实验,验证了所设计声级计的正确性,性能达到了Ⅰ型声级计指标。所开发的多功能虚拟声级计程序模块化、灵活,很容易和其它设备集成,可应用于工业过程需要噪声或声级测量的众多场合。 相似文献
6.
7.
8.
提出了采用正交小波变换进行计权声级测量的方法 ,克服了传统计权声级测量系统中采用模拟计权网络的缺点 ,比采用短时傅里叶变换方法更能反映人耳对噪声的主观感觉特性。理论分析和仿真计算表明 ,该方法是可行的。为了进一步提高计算精度和减少计算复杂度 ,给出了对应于 IIR滤波器的正交小波变换、自适应小波包变换和匹配小波变换等三种可能的改进方法。 相似文献
9.
采用声发射技术对工件材料为A16061-T6的微切削表面轮廓进行了实时测量.采集监控微切削加工表面时产生的声发射均方根信号,并与表面轮廓仪测得的结果进行对比.研究表明,声发射均方根信号与微切削表面形貌很好的相对应,因此,声发射技术适于微切削表面形貌的监测.研究了切削用量(每齿进给量和主轴转速)与表面形貌之间的关系,微切削的每齿进给量对表面粗糙度影响较大. 相似文献
10.
11.
12.
13.
Junhong Zhang Hai Liu Fengrong Bi Guangjian Ni Guichang Zhang Jiewei Lin Hanzhengnan Yu 《机械工程学报(英文版)》2012,25(4):809-815
There are more researches on engine fan noise control focusing on reducing fan noise level through optimizing fan structure,and a lot of research achievements have been obtained.However,researches on the effect of fan noise to engine noise quality are lacking.The influences of the effects of fan structure optimization on the engine noise quality are unclear.Thus,there will be a decline in fan noise level,but the deterioration of engine noise quality.Aiming at the above problems,in consideration of fan structure design and engine noise quality,an innovative method to analyze the contribution of fan noise to engine noise quality using psychoacoustic theory is proposed.The noises of diesel engine installing different cooling fans are measured by using the acoustic pressure method.The experiment results are regarded as analysis samples.The model of sensory pleasantness is used to analyze the sound quality of a diesel engine with different cooling fans.Results show that after installing 10-blade fan in medium diameter the sensory pleasantness at each test point is increased,and the increase is 13.53% on average,which indicate the improvement of the engine noise quality.In order to verify the psychoacoustical analysis,the subjective assessment is carried out.The test result shows the noise quality of engine installed10-blade fan in medium diameter is most superior.1/3 octave frequency spectrum analysis is used to study the reason of the improvement of engine noise quality.It is found that after installing proper cooling fan the sound pressure level below 400 Hz are obviously increased,the frequency assignment and spectral envelope are more reasonable and a proper cooling fan can optimize the spectrum structure of the engine noise.The psychoacoustic study is applied in the contribution of fan noise to engine noise,and the idea of engine sound quality improvement through the structure optimization is proposed. 相似文献
14.
声功率级的测量中,声强法比声压法具有更大的优越性。以一台2XZ-4A型旋片真空泵为测试对象,通过比较声压法与扫描声强法的测量结果,证明声强技术在旋片真空泵声功率级的测量中具有足够高的精度,能够在任何环境下准确评价泵产品的噪声性能,为精确测量机械设备噪声源的声功率级提供了一种参考方法。 相似文献
15.
Hyun-Hoo Lee Sung-Jong Kim Sang-Kwon Lee 《Journal of Mechanical Science and Technology》2009,23(4):1182-1193
The gear whine sound of an axle system is one of the most important sound qualities in a sport utility vehicle (SUV). Previous
work has shown that, because of masking effects, it is difficult to evaluate the gear whine sound objectively by using only
the A-weighted sound pressure level. In this paper, a new objective evaluation method for this sound was developed by using
new sound metrics, which are developed based on the increment of signal to noise ration and the psychoacoustic parameters
in the paper, and the artificial neural network (ANN) used for the modeling of the correlation between objective and subjective
evaluation. This model developed by using ANN was applied to the objective evaluation of the axle-gear whine sound for real
SUVs and the output of the model was compared with subjective evaluation. The results indicate a good correlation of over
90 percent between the subjective and objective evaluations.
This paper was recommended for publication in revised form by Associate Editor Yeon June Kang
Professor Sang-Kwon Lee received a Ph.D. degree in ISVR (Institute of Sound and Vibration Research) from Southampton University in 1998. He joined
Hyundai Motor Research Center in Korea, working with the Automotive Noise and Vibration Control Group from 1985 to 1994. He
has been the Professor at the Department of Mechanical Engineering, Inha University, Inchon, Korea, since March 1999. His
research interests are the digital signal processing, NVH (noise vibration harahness), condition monitoring, product sound
quality design and active control. 相似文献
16.
针对传统A计权声压级评价指标对噪声低频成分衰减较大,常常出现车内声压级达标,声品质不合格的问题。引入心理声学参数的响度参量,利用虚拟仿真技术分析评价车内声学特性。建立驾驶室声-固耦合有限元模型,结合试验激励数据,进行基于模态的声学响应计算。在Matlab平台上,建立车内声品质客观心理声学参数响度的计算模型,对比预测驾驶室内场点的声压级和响度分布,结合声压级和响度结构板块贡献量分析,研究声压级和响度参量评价驾驶室结构特性的差别并识别驾驶室主要噪声源。以此为基础指导优化驾驶室结构阻尼铺设位置,综合提高车内声学品质。 相似文献
17.
为探究改变叶顶间隙对矿用对旋式轴流风机气动噪声的影响,建立不同叶顶间隙的风机三维模型,并结合风机性能试验验证模型的正确性。利用Fluent对风机进行定常模拟、非定常模拟和噪声预估,分析了声功率级和声压级随叶顶间隙的变化情况。结果表明:叶根与轮毂交界处、叶顶间隙处和相邻两叶片中间部位的声功率级随间隙的增加而增大,且叶顶处吸力面声功率级高于压力面。不同间隙下风机的A级声压值总体上呈先急剧下降后上升再逐渐下降的趋势,间隙变大后,风机在各监测点处的A级声压值随之增大。与高频处相比,间隙对中低频处的A级声压值影响更加显著。 相似文献
18.
车身低噪声设计新方法 总被引:1,自引:0,他引:1
为降低车内低频噪声而改进车身结构时,现有方法往往需要较长周期,因此研究一种可快速、准确定位车身结构薄弱处,以及明确车身结构刚度调整方向的车身低噪声设计新方法。将一般腔体结构的内部声场计算公式分解为5个部分,并讨论这5个部分的特点,确定进行声压响应幅度判定参数研究时,采用的6种关键组合。以含一个弹性面的刚性长方体结构声腔耦合系统为对象,讨论6种关键组合的关系;分析发现振型耦合系数、频率重叠系数、结构振型在激励点处分量等三者的乘积能够完全体现声压响应信息,可作为声压响应幅度判定参数。详细分析声压响应幅度判定参数的特点,可满足预期研究目标;基于该参数,提出一种车身结构低噪声设计的新方法。利用该新方法,对某轿车车内低频噪声进行优化,进一步的频率响应计算结果表明,车身结构优化后驾驶员测点声压级平均降低3 dB,最大降低10 dB。 相似文献
19.
基于GA-BP的汽车风振噪声声品质预测模型 总被引:1,自引:1,他引:0
目前对于汽车风振噪声的优化研究主要以声压级(Sound pressure level,SPL)作为单一评价指标,既不能全面反映噪声的物理属性,也无法考虑人耳对噪声的主观认知过程。为准确评价风振噪声,引入声品质,运用大涡模拟(Large eddy simulation,LES)对风振噪声进行数值仿真,根据实车道路试验判断仿真的准确性;对仿真结果进行声品质客观评价与主观评价,综合声品质客观评价参数与声品质主观评价试验结果建立BP神经网络预测模型;利用遗传算法(Genetic algorithm,GA),进一步对BP神经网络的结构参数进行优化,建立GA-BP声品质预测模型。研究结果表明,GA-BP声品质预测模型在训练速度和预测精度上都优于BP神经网络预测模型。预测模型基于声品质主客观评价结果,其预测值可以代替传统的声压级评价指标,为风振噪声提供更为准确合理的评价。 相似文献