Within the CFM RISE program, Open Fan architectures are studied to meet challenging goals in fuel consumption, gas emissions, and noise levels. In this challenging and innovative frame, the perceived noise in cabin in flight is among the key drivers. Indeed, the acoustic field produced by the propeller blades directly impinges the fuselage without attenuation or modification by a duct as in a turbomachinery. Furthermore, the propeller and aircraft speeds are beyond those of a usual propeller driven regional aircraft and the propeller aerodynamic field could be associated with shock waves. The pressure field produced by the propeller that excites the fuselage needs to be investigated to be able to evaluate the role of the propeller noise in cabin in flight, and to be able to design quieter configurations.
Applications are invited for a 3-year PhD studentship to focus on the modeling of the excitation on the fuselage caused by the propeller. Namely, the PhD student will predict the propagation of the flow field produced by the propeller up to the fuselage including non-linearity effects caused by the shock amplitudes, fuselage boundary layer refraction and airframe scattering. After a bibliographic study, the PhD student will put in place a numerical modelling using a Euler solver. In particular, a specific modelling and development will be needed to introduce the proper excitation. Then, the PhD student will perform numerical investigations to identify the impact of the different physical mechanisms and parameters. He/She will finally draw rules and simplified laws to estimate the pressure field exciting the fuselage as a function of identified driving parameters. This 3-year PhD project is part of the ARENA research program. Funded by the ANR, this is a partnership between the Ecole Centrale de Lyon (ECL) and Safran Aircraft Engines.