Richard Glassock is a Research Fellow in Hybrid Electric Propulsion Systems for Aircraft at the University of Nottingham Faculty of Engineering. He is working with Air Race E and leading the project to build the world’s first electric race plane through the University of Nottingham’s Beacons of Future Propulsion programme.
We caught up with Richard Glassock and asked him some questions about the potential future of Air Race E and how the planes will work.
How can Air Race E help change aircraft for the better?
The Air Race E technology demonstrator program has three main aims for the future: to help develop technology for the future of air travel; to promote the use of cleaner methods of air transport, which is believed to currently account for around 2% of the world’s CO2 emissions and finally, for people to be able to enjoy the high speed thrill of an air race.
With that being said, how will the planes work?
The main component, which the University of Nottingham is developing for the aircraft, is the propulsion system. We intend to provide a ‘plug and play’ system, including a battery powered integrated electric motor, and an electronics system. The system being developed at the present time is a custom version of this technology, which requires months of careful integration and work to ensure the optimal performance and safety of the planes.
How will this new propulsion system impact the plane and its performance?
The speed will likely be higher than the best performing current petrol engine types. The new rules have baselined 150kW (200HP) electric motors, whereas only the most highly tuned internal combustion engines (ICE) in this class can output that much power. At this high power level, electric motors should be much more reliable than the highly-stressed old style engines and this will promote closer, more competitive racing. We should also see improvements in propeller efficiency, converting that power into thrust.
The maximum speed of the aircraft occurs when the thrust equals the drag, so we look to create the maximum thrust for the given maximum power and to reduce the drag as much as possible. Electric propulsion can potentially help reduce drag for at least 2 reasons; 1) the motor shape is more slender than the engine shape, so the front of the fuselage can be more slender which can reduce aerodynamic drag and 2) the cooling requirements of the electric propulsion system should be reduced compared to the ICE system. The cooling system produces drag because some airflow must be redirected to engine cooling fins and oil cooling heat exchangers etc. The ICE system is about 25% efficient at converting fuel energy into output shaft power, this means that 75% of the energy must be released in other ways. Much of this waste heat leaves with the exhaust gases, but much remains to be transferred using cooling air into the cowling, and this causes drag. The electric motor system could be up to 90% efficient, and therefore less cooling air is required.
Finally, it is very important to note that the electric propulsion system will produce approximately the same power no matter what altitude it is being operated at. The old engines produced proportionally less power at higher altitudes and depending on the temperature and pressure of the day, much less. So, putting all these factors together, we should see higher performance for racing in the future.
Are there any downfalls with this new technology?
One of the main obstacles with producing large airliners with this technology is the weight of the batteries and the system involved. Today’s batteries can only supply around 2% of the energy that jet fuel can. However, the efficiency of the motor in using this energy is between 2 to 4 times better than the ICE system. Electrical energy storage capacity is slowly being pushed further as the new technology required is being developed. There are other solutions being considered, such as hybrid technology (partially fuel based engines), as seen in hybrid cars. This may be far more effective than a purely battery or ICE system. We are expecting electric propulsion technology to be scaled up to 200+ seaters by the year 2050. It is predicted that planes of this nature will produce up to 70% less noise, carbon and nitrogen oxide pollution than today’s fuel-based planes.
Is there anything interesting or quirky you can reveal about the plane?
Well, one thing that a few people have found interesting is the batteries themselves. We’ll actually have three fireproof carbon containers within the plane. The batteries will be housed inside these boxes to contain them and lower any risk. When you look at the batteries, they actually look like the old mobile phone style batteries, but of course rather than one of these batteries, we will have hundreds.
Richard’s team will have the Cassutt (G-LEFT) built and in testing by September this year and will flight test this year too. The team will then begin Phase 2, which develops much higher performance and leading technology.