According to the call topic, the goal of the project was to optimise the design of a subsonic jet pump, to reduce the noise level as much as possible. The optimisation of the subsonic jet pump was done from the aerodynamic point of view and two type of analyses were used, a RANS analysis as a “fast-screening” procedure to be able to identify using such techniques a trend in the flow behaviour when performing a parameter study and a time dependent analysis with the more time-consuming but more accurate and more reliable, Large Eddy Simulation, for only the most promising or thought-provoking configurations.

The acoustic treatment for further reducing the noise levels of the jet pump, in any configuration, is the application of noise treatment in the mixing part, and/or in the diffuser. From the acoustic treatment standpoint, there are two ways of attaching the noise reduction problem. First, the passive acoustic treatment, and second, which was considered in the following, composed of resonant - absorbent structures. Taking into consideration the aerodynamic optimisation and the acoustic treatment a demonstrator with different configurations were tested in the anechoic chamber where the velocity field and acoustics were measured and compared with the numerical results.