Sound wave transmission on quasicrystal cylindrical shells with internal and external airflow

The sound transmission through a multilayered quasicrystal cylindrical shell with internal and external airflow is used to model the transmission of airborne sound into the aircraft interior. Based on the quasicrystal elastodynamics theory, the state equations of the whole shell are derived in the partial differential form using the state space method. The governing equations of arbitrary thickness shells are obtained by means of general and accurate field expressions. The external and internal fluid mediums of the shell are used to simulate the air inside and outside the cabin and move with constant velocities. The Bessel and Hankel functions are introduced to characterize specific acoustic wave equations, and further to couple with the shell equations. An exact solution of the transmission loss is presented in a series form under satisfying the fluid‐structure interaction boundary conditions. The numerical examples indicate that the presented model is stable and precise through convergence verification. The numerical results exhibit the influences of different source conditions, structural properties, and flight conditions on the transmission loss, in which the flight altitude, Mach number, and incidence angle affect the transmission loss by changing the axial and radial wave numbers. In addition, the initial stresses artificially added to quasicrystal shells to overcome the residual stress have no effect on transmission loss.