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

This paper deals with the response of a distributed air transmission line with laminar flow subjected to an impulse, step, or arbitrary periodic excitation. The rational is based on the inverse Fourier transform: R(¿) = F^-1 {G(j¿) * P1 (j¿)} where R(¿) is the response, G(j¿) the system frequency function, and P1(j¿) the frequency spectrum of the input function. For input flow prediction, G(j¿) is the input admittance. G(j¿) 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.