Numerical method to study the exhausted gasses of an helicopter engine

The aim of this thesis is to develop and analyze different configuration of the nozzle of a helicopter engine to try to search some design that could improve the mass flow coming from the secondary inlet, but keeping the same pressure losses. After considering the characteristics of the flow inside the nozzle, the mathematical formulation of the problem is proposed. Then, the numerical implementation is presented and for this task, it was chosen the open source softwares OpenFOAM and SALOME. Then the CAD of the original component was prepared for the CFD analysis, simplifying unnecessary details that would blow up the computational cost. It was performed a steady RANS simulation and the results obtained were confronted with the ones computed with the Company CFD software (STAR-CCM+) and to some data provided by the engine manufacturer, such as the static pressure at the primary inlet to have a response on the quality of our model. After this check, different geometries (6 in total) were designed and simulated and the results were compared to the default configuration. In the performance analysis were confronted some relevant quantities such as the pressure at the primary inlet (to have an indication on the pressure losses), the secondary inlet mass flow, the standard deviation, the average and the maximum temperature on the external wall boundary (to try to get some information on the thermal load at the surface of the nozzle). Then we had a deeper look on each design case, to try to better understand each flow behavior. At the end of the analysis unfortunately none of the proposed design significantly improved the system; at best it was found a more compact design (so lighter) that behaves equally to the default one.