Numerical simulation of an acoustic tube

In this work, we introduce a staggered finite difference method to analyze and simulate the generation and behavior of sound waves inside a tube. We describe a special numerical treatment on the boundary conditions which model reflection and transmission phenomena by means of the acoustic impedance concept. Through an exhaustive sampling of frequencies and the fast Fourier transform (FFT) a modal analysis is performed when the air inside the tube is subjected to both harmonic and random disturbances. Finally, we analyze the quality factor behavior of the acoustic system to confirm its exponential character as well as its dependence on the acoustic impedance.  The results show the utility of the method in the acoustic phenomena simulation such as reflection, transmission, dissipation of sound waves and resonance in bounded domains. The propose method allows analyzing general cases such as the dispersion of non-harmonic sound waves