Applications are invited for a fully funded PhD studentship within the Rolls-Royce University Technology Centre (UTC) in Aero Systems Design, Integration & Performance at Cranfield University.
The focus of this Doctoral research is on the use of a Variable Pitch Fan (VPF) to generate reverse thrust during the landing run of the aircraft. The work explores VPF reverse thrust behaviour using an integrated airframe-engine computational research model with focus on stable engine operation and the development of novel design features to improve reverse thrust performance.
This research programme spans for 3 years and is in close collaboration with Rolls-Royce plc (fully funded by Rolls-Royce plc via the UTC at Cranfield).
A Variable Pitch Fan (VPF) can be used to ensure stable and optimal fan operation in different parts of the aircraft mission profile. This can lead to significant improvement in the overall mission fuel burn of future ultra-high bypass ratio engines. Additionally, if the VPF is used to generate reverse thrust, significant weight and aircraft installation drag reduction can be obtained by the elimination of the traditional cascade thrust reverser unit which can thereby pave the way for using modern low-drag ‘slim-line’ nacelles. The ability of the VPF to generate reverse thrust in an aircraft has been demonstrated by using an in-house developed integrated airframe-engine research model. The model is capable of simulating the reverse thrust mode operation of the VPF during the entire aircraft landing run and has provided new insights into the reverse thrust flow field. As an extension of this capability, this PhD will explore the ability of the core engine to sustain the VPF operation in reverse thrust while operating in an unconventional, complex, distorted and unsteady flow field. Thereafter, novel design alternatives to improve reverse thrust performance will be considered.
The study will look into the following broad areas of interest amongst other:
• The stable operation of the core engine in a complex distorted flow field with significant pressure loss • The operability of the compressors in terms of working lines • Details on the fan aero flow field for various operational settings to optimize VPF design • Novel design features that can improve reverse thrust performance • Identification of regions of aerodynamic modelling that require validation and development of validation methods