为实现汽车前围板隔声薄弱部位的准确识别,文章提出了基于快速傅里叶变换(Fast Fourier Transform,FFT)和正交匹配追踪(Orthogonal Matching Pursuit,OMP)的反卷积(Deconvolution Approach for the Mapping of Acoustic Sources,DAMAS)...为实现汽车前围板隔声薄弱部位的准确识别,文章提出了基于快速傅里叶变换(Fast Fourier Transform,FFT)和正交匹配追踪(Orthogonal Matching Pursuit,OMP)的反卷积(Deconvolution Approach for the Mapping of Acoustic Sources,DAMAS)波束形成方法(FFT-OMP-DAMAS)。该方法基于声源稀疏分布假设,利用正交匹配追踪思想求解反卷积问题,并进一步结合傅里叶变换和点扩散函数空间转移不变假设降低计算维度。在混响室-消声室内,分别利用延迟求和方法,DAMAS方法和FFT-OMP-DAMAS方法进行了某汽车前围板隔声薄弱部位识别试验,结果表明:FFTOMP-DAMAS方法能够有效抑制旁瓣和伪源,有效缩减主瓣宽度,从而准确识别汽车前围板隔声薄弱部位,且相较于传统的DAMAS方法,文中提出的FFT-OMP-DAMAS方法能获得更清晰的成像结果,计算效率有了明显提高。展开更多
建立了包含27个子系统的前围板SEA(statistical energy analysis)法模型,通过理论计算确定了进行SEA分析所需的基本参数.求解隔声量并与试验结果对比,其吻合良好,验证了SEA法用来计算镁质前围板在高频段隔声量的有效性.根据各个子系统...建立了包含27个子系统的前围板SEA(statistical energy analysis)法模型,通过理论计算确定了进行SEA分析所需的基本参数.求解隔声量并与试验结果对比,其吻合良好,验证了SEA法用来计算镁质前围板在高频段隔声量的有效性.根据各个子系统的声透射曲线可知,在高频段,有必要对前围板整个模型而非局部进行声学优化.据此优化设计了一种复合前围板.为了更加客观地评价其优化效果,提出用降噪效率作为前围板声学优化的一个综合评价指标.通过改变多孔吸声层和空气层的厚度,综合考虑降噪效率、车内空间的限制、轻量化和成本的要求,确定其最优方案的空气层为1,mm,多孔吸声层为10,mm.声学优化后的前围板较优化前隔声量平均提高了20.2,d B,这对工程实际应用具有十分重要的意义.展开更多
The coupled model of a four-cylinder internal combustion engine and a dash panel was constructed to analyze the relationship between the engine noise and interior noise of an automobile. Finite element analysis, flexi...The coupled model of a four-cylinder internal combustion engine and a dash panel was constructed to analyze the relationship between the engine noise and interior noise of an automobile. Finite element analysis, flexible multi-body dynamics, and boundary element analysis were integrated to obtain the tetrahedron-element models, structural vibration response, and radiated noise,respectively. The accuracy of the finite-element model of the engine was validated by modal analysis via single-input multi-output technology, while the dash panel was validated by sound transmission loss experiment. The block was optimized to reduce the radiated acoustic power from the engine surface. The acoustic transfer path between the engine cabin and passenger compartment was then established. The coupled analysis results reveal that the interior noise is optimized due to the engine noise reduction.展开更多
文摘为实现汽车前围板隔声薄弱部位的准确识别,文章提出了基于快速傅里叶变换(Fast Fourier Transform,FFT)和正交匹配追踪(Orthogonal Matching Pursuit,OMP)的反卷积(Deconvolution Approach for the Mapping of Acoustic Sources,DAMAS)波束形成方法(FFT-OMP-DAMAS)。该方法基于声源稀疏分布假设,利用正交匹配追踪思想求解反卷积问题,并进一步结合傅里叶变换和点扩散函数空间转移不变假设降低计算维度。在混响室-消声室内,分别利用延迟求和方法,DAMAS方法和FFT-OMP-DAMAS方法进行了某汽车前围板隔声薄弱部位识别试验,结果表明:FFTOMP-DAMAS方法能够有效抑制旁瓣和伪源,有效缩减主瓣宽度,从而准确识别汽车前围板隔声薄弱部位,且相较于传统的DAMAS方法,文中提出的FFT-OMP-DAMAS方法能获得更清晰的成像结果,计算效率有了明显提高。
文摘建立了包含27个子系统的前围板SEA(statistical energy analysis)法模型,通过理论计算确定了进行SEA分析所需的基本参数.求解隔声量并与试验结果对比,其吻合良好,验证了SEA法用来计算镁质前围板在高频段隔声量的有效性.根据各个子系统的声透射曲线可知,在高频段,有必要对前围板整个模型而非局部进行声学优化.据此优化设计了一种复合前围板.为了更加客观地评价其优化效果,提出用降噪效率作为前围板声学优化的一个综合评价指标.通过改变多孔吸声层和空气层的厚度,综合考虑降噪效率、车内空间的限制、轻量化和成本的要求,确定其最优方案的空气层为1,mm,多孔吸声层为10,mm.声学优化后的前围板较优化前隔声量平均提高了20.2,d B,这对工程实际应用具有十分重要的意义.
基金Project(2011BAE22B05)supported by the 12th Five-year National Key Projects of Science and Technology Support Plan,China
文摘The coupled model of a four-cylinder internal combustion engine and a dash panel was constructed to analyze the relationship between the engine noise and interior noise of an automobile. Finite element analysis, flexible multi-body dynamics, and boundary element analysis were integrated to obtain the tetrahedron-element models, structural vibration response, and radiated noise,respectively. The accuracy of the finite-element model of the engine was validated by modal analysis via single-input multi-output technology, while the dash panel was validated by sound transmission loss experiment. The block was optimized to reduce the radiated acoustic power from the engine surface. The acoustic transfer path between the engine cabin and passenger compartment was then established. The coupled analysis results reveal that the interior noise is optimized due to the engine noise reduction.
