Noise Barrier Simulated by Rigid Screen with Back Wall

The problem related to noise barriers is simulated by a still, single‐frequency, three‐dimensional sound source located within two parallel screens with rigid back walls. The solution of a reflection sound field is represented by an asymptotic solution, which is derived by the method of steepest descent. We find that there is a periodic relationship between the screen‐reflection coefficient and the gap‐to‐wavelength ratio $(d/\lambda )$ of the noise barrier. And there is another parameter called screen Reynolds number $\left(R_e\right)\text{,}$ which regularly affects the value of the screen‐reflection coefficient. The optimum choice of noise barrier that minimizes reflection within parallel noise barriers, according to the numerical results, is $R_e=1\text{,}$ and $d/\lambda =1/4\text{.}$ We also find that increasing the height of the noise barrier in order to improve its noise‐control effect is not economical.