Acoustical characteristics of micro-pressure wave and sensor selection

The measurement results of micro-pressure wave can be easily changed when different types of pressure sensor used in scaled model and real train tunnel experiments. The time-frequency characteristics of micro-pressure wave were presented at different train speeds by using the experiments data. The CAA model with high-order spectral difference method was used to predict the wave radiation from tunnel portal. On this basis, the measurement results of micro-pressure wave by using three different types of sensors are checked and discussed which are useful for the sensor selection. The results show that micro-pressure wave energy is mainly distributed in the region of the infrasonic wave. The tunnel outlet aerodynamics noise source is mainly distributed within the scope of 2 times the pipe diameter. The amplitude and the frequency spectrum characteristics wave should be considered in formulating the micro-pressure wave industry standard.