Quieter jet engines – and kinder to the environment

The jet airliners of the future will be significantly quieter and more environmentally friendly with the help of engineers at The University of Nottingham.

Researchers have been awarded £830,000 (€1.2m) to explore new design methods that could reduce the noise of jet engines while at the same time cutting the amount of carbon dioxide (CO2) they release into the atmosphere. They will play a key part in a new research project called VITAL — which stands for EnVIronmenTALly Friendly Aero Engine.

A team at The University of Nottingham will join a prestigious research programme bringing together the best of European aircraft engine expertise. Of 16 European universities involved — from Sweden, Germany, Austria, France, Italy and the UK — the Nottingham team has won the biggest slice of European Commission funding devoted to universities. Professor Tom Hyde, head of the School of Mechanical, Materials & Manufacturing Engineering, said: “This is a major new development for the research groups in the School and recognises our internationally-leading reputation in aeroengine technology.”

VITAL is a four-year programme involving a consortium of 53 partners including all major European engine manufacturers, Airbus and leading European universities. It focuses on the low-pressure parts of the engine, evaluating new engine designs including counter-rotating fans, lightened fans, highly-loaded turbines and turbines with fewer blades. The weight reduction will enable the development of very high bypass ratio engines that reduce noise by between 5dB and 8dB while also decreasing CO2 emissions.

Nottingham’s researchers, who are all from the School of Mechanical, Materials & Manufacturing Engineering, will be working on three major projects with a budget of £830,000 (€1.2m). This is more than the combined awards of all the other three UK universities involved. In order to achieve VITAL’s noise reduction targets, the main low-pressure drive shaft must transmit a higher torque without increasing the size of the shaft or the weight of the engine. The target for Nottingham’s researchers is a 50% increase. Dr Ed Williams, who will be leading this part of the programme, said: “This cannot be achieved with existing technology, so we will be developing new multi-alloy designs and exploring the use of metal matrix composites.”

The casing of the engine is its backbone, transferring the thrust from the engine to the aircraft. Nottingham will be developing new automated fabrication techniques for these complex structural components, which are made from titanium alloys. Dr Phil Webb, an expert in robotic welding, said: “These techniques will lead to a 15% weight reduction and a 30% lead time reduction in development and production.” Many parts of the casing have to operate at high temperatures and structural integrity is of paramount concern to the designer. Prof Adib Becker said, “We will be developing new methods of predicting the life of these structures using advanced computer modelling of combined creep and fatigue mechanisms.”

The total budget for the VITAL programme is €90m, including €50m in funding from the European Commission.