空气声学

通过计算流体力学方法计算出了喷射流的速度场分布和湍流动能分布，使用计算空气声学的方法，得到了喷射噪声的频谱特性。

The velocity and turbulent kinetic energy distribution is calculated by computational fluid dynamics ( CFD ) method . The spectrum characteristic of flow induced noise is calculated by computational aero-acoustics ( CAA ) method .

汽车空气滤清器声学性能数值计算及分析

Numerical Calculation and Analysis of Acoustic Characteristics of Automotive Air Cleaner

由于空气的非线性声学效应，在传播过程中声波中的音频信号会自解调出来，可以被人耳直接听到。

During the propagation of the sound wave , the audio signal is regenerated by self-demodulation due to the nonlinearity of air .

利用氢气和空气之间在声学特征上的显著差异，以石英作为压电材料，并且采用双压电电极的工作方式，采用了正逆两种压电效应，检测出不同浓度氢气的谐振频率。

The hydrogen sensor based on ultrasonic resonator uses the significant characteristics differences between the hydrogen and air , selects quartz as the piezoelectric material , uses two inverse piezoelectric effects to detect the resonant frequency of different concentrations of hydrogen .

由于一维平面波理论只适于低频分析，为了扩大分析的频率范围，采用了三维有限元数值方法分析空气滤清器的声学特性。

In view of that the plane wave theory is suitable only in lower frequency range , the three-dimensional finite element method is applied to analyze the acoustic characteristics of air cleaner in the present study for broadening the frequency range .

四角切圆炉内空气动力特性的声学测量试验

Testing the aerodynamic characteristics in a tangential boiler by acoustic measurement