Surface roughness is currently the highest priority problem within the gas turbine industry. It is really exciting to be working on this research and to receive recognition from the CSAR for my efforts.

PhD student Abigail Berhane

Abigail, who is based at the Department’s Whittle Laboratory, has been presented with a PhD Student Award For Applied Research by the Cambridge Society for the Application of Research (CSAR), along with the sum of £1,000 to support her in the final stages of submitting her PhD.

The Award is intended to recognise outstanding research with real-world application and to assist students to pursue their research or careers.

Abigail is a research student with the ESPRC Centre for Doctoral Training (CDT) in Future Propulsion and Power. The CDT connects the brightest minds in research with the most challenging problems in the industry.

With the aviation industry having adopted the goal of reaching net zero carbon emissions by 2050, Abigail has been working in collaboration with Rolls-Royce to tackle the problem of ‘surface roughness’ on the aerodynamic performance of gas turbine blades.

Surface roughness influences engine performance – it is a contributing factor to the amount of specific fuel consumed by a gas turbine aero engine to generate thrust. Gas turbines are widely used in aircraft propulsion and power generation.

“Surface roughness is currently the highest priority problem within the gas turbine industry,” said Abigail. “It is really exciting to be working on this research and to receive recognition from the CSAR for my efforts.”

Together with Rolls-Royce, she has developed a novel experiment that can decompose the effects of roughness to its individual features, allowing engine designers to better predict the effects of different surfaces on thrust.

“This is critical for the design, development and operation of aero engines, helping to reduce the lifetime environmental impact of aviation and any other industry hindered by aerodynamic inefficiencies,” added Abigail.

Abigail’s experimental methodology: 'scan; scale; print; measure', enables any engine component to be scanned in high resolution, preprocessed/scaled, 3D printed and then measured in a wind tunnel.

“For the first time, complete control over surface roughness features for testing can be gained via this process. Through this, isolated parametric studies can be performed to understand how different geometrical features of a rough surface affects its aerodynamic penalty.”

Abigail’s new method supersedes traditional methods adopted by the gas turbine industry, which were used for assigning an aerodynamic penalty to a rough surface. Examples include relying on limited measurements of a single-length scale such as average roughness height, and incomplete methods of correlation analysis from the 1930s.