The Open and Blocked Distributed Air Transmission Lines by the Fast Fourier Transform Method

This paper deals with the digital computer simulation of a distributed air transmission line subjected to an impulse, step, or arbitrary excitation. The rationale is based on the inverse Fourier transform principle: where R(t) is the response, G(jω), the system frequency function, and P₁(jω), the frequency spectrum of the input function. For input flow prediction, G(jω) is the input admittance. G(jω) represents the transfer function for pressure calculation. The predicted dynamics of a blocked and an open line subjected to arbitrary periodic excitation are compared with experimental measurements. The paper also presents the mathematical proofs to illustrate the functional behaviors of G(jω) as ω is varied from −∞ to −∞.