Analytical methods address the need to quickly determine the effect of indirect combustion noise on farfield acoustic emissions and combustion instabilities in order to account for them in new designs. A 2D axisymmetric model for indirect combustion noise through a non-compact nozzle was recently developed by Zheng et al. with this ambition [PhD Thesis, 2016]. An original Computational AeroAcoustics (CAA) approach is applied to serve as a reference case within a framework close to the model’s hypotheses. Results from computations with a Euler mean flow field are compared to the model. Very good agreement is observed, validating the approach. The data is also compared to a 1D model for the non-compact nozzle elaborated by Giauque et al. [J. Eng. Gas. Turb. Power, 134, 2012], demonstrating the importance of 2D effects and the role of radial deformation of the entropy wave.