In this paper, numerical analysis of noise radiation from a lined turbofan exhaust cowl is carried out using a linearized Euler solver. In particular, the additional noise reduction by a lined afterbody concept is investigated. This concept involves extension of acoustic treatment to the exterior surface of the engine core nozzle cowl beyond the bypass nozzle exit. Full influence of non-uniform background flows through the ducts and the jets on sound propagation and radiation is included in the computations. The mean flow is obtained from Reynolds Averaged Navier-Stokes solutions using the Fluent solver. The numerical difficulties present with the sheared flows, both in ducts and jets, are overcome by solving the equations directly in frequency domain, using the code FLESTURN, which has been developed recently in the frame of the European FP6 project TURNEX. Results obtained at various flight regimes and frequencies show promising rearward fan noise reduction by this lined afterbody concept. Copyright © 2008 by AIRBUS S.A.S.