In the present work, the generation and propagation of entropynoise is computed using acompressible URANS approach in combination with appropriate acoustic boundary conditions. The EntropyW aveG enerator (EWG) experiment is best suited for validating the proposed approach and for investigating the acoustic sources of entropyn oise. The EWG involves an on-reactive tube flow, where entropym odes are imposed to an incoming air flowbyusing aheating module. The generated temperature non-uniformities are accelerated with the mean flowdownstream in aconvergent divergent nozzle, thus producing entropynoise. Simulation results of pressure fluctuations and their spectra for adefined standard configuration as well as for different operating points of the EWG agree very well with the respective experimental data. Additionally,a na nalysis of the acoustic sources wasperformed. Forthis purpose the acoustic sources caused by the acceleration of density inhomogeneities were calculated. Fort he first time, an umerical method is introduced for the localization of the acoustic sources of entropynoise in acceleration/deceleration regions. PACS no. 43.28.Kt, 43.28.Py 470 ©S.Hirzel Verlag · EAA Mühlbauer et al.:N umerical investigation of entropynoise ACTA ACUSTICA UNITED WITH ACUSTICA Vol. 95 (2009)