利用声强度和激光测速方法实现声学流场的可视化
Although acoustics consists in the propagation of an oscillatory disturbance of localpressure, particle velocity, density and temperature, sound measurement is often assimilatedto pressure measurement. This is because for decades only pressure fluctuations wereaccessible and because their relation with the other oscillatory quantities is well known underlinear acoustic approximation and in simple configurations. Such a correct description of theorigins of sound has long been known from the theory of sound, but there is a bad habit ofacousticians to use the descriptions of sound as acoustic pressure only. Meanwhile, a soundwave is a form of energy transport in the field and has the vectors features. Sound intensity(SI) as a vector variable inseparably couples the acoustic particle velocity (called alsoacoustic velocity). and acoustic pressure (Ia=p v) and represents a stream of acoustic energyflowing in the field. This vector parameter of acoustic wave can be measured with specialsound intensity probe and can be easily shown in a graphical form.