As part of its drive to create more efficient propulsion for jetliners, Rolls-Royce is building an engine whose diameter is only slightly smaller than that of a London Underground tunnel, and 25% more efficient than its 1990s-designed predecessors.
The huge size allows more air to be shifted through the engine with a larger fan, but without proportionally increasing the required power. Even so, it is pushing the limit of what can be squeezed from turbofan engine design because of size limits and temperature.
The company is also working in other directions toward reduced-carbon aviation, including creating greener fuels for existing engines, starting with biofuels and synthetic fuels. At a step past that, the company hopes, it will be able to develop a fuel that bonds hydrogen with recycled carbon dioxide to produce a nearly waste-free fuel.
Rolls-Royce is also working on new technology for electric aviation of a sort, in this case comparable to a hybrid car. The company is developing a generator that would be integrated with the engine, producing electricity while the engine is running, and then feeding electric power to operate the plane until a fuel burn is needed again. It's a possible solution for large planes with long routes that can't run on battery power because of the huge battery weight that would be required.