This paper presents an analytical and numerical investigation of an impedance tube in the presence of a mean temperature gradient. Full Navier-Stokes simulation of the acoustic wave propagations through an impedance tube in the presence of a mean temperature gradient without mean air flow is investigated. Results from the simulations are compared with an analytical model of the behaviour of one-dimensional oscillations in an impedance tube with an axial temperature gradient in the absence of mean flow. Time and axial distance dependent acoustic pressure and velocity are visualised as 3D surface plots. The agreement between simulation and the analytical model is shown to be very good and represents a baseline validation of the numerical methodology for the simulation of impedance tubes in the presence of temperature gradients
