Rolls-Royce has conducted icing tests on a demonstrator engine equipped with a lean-burn combustor to be used in the manufacturer's Advance and UltraFan future powerplant programmes.

The UK manufacturer says that the modified Trent 1000 engine – dubbed ALECSys, or advanced low-emission combustion system – underwent cold-weather rig trials in Canadian province Manitoba at temperatures of -20°C (-4°F) a month after initial ground tests at R-R headquarters in Derby.

R-R told FlightGlobal in January that the ground tests had been completed that month.

The combustor features two different fuel-distribution systems to facilitate more efficient mixing of air and fuel during take-off, climb and cruise.

"Tests have so far shown a halving of NOx [emissions] at cruise, compared to today's levels," says R-R.

Andy Geer, the manufacturer's chief engineer and head of technology programmes, says that while computer simulation has provided "in-depth understanding" of the system's operation in extreme temperatures, the cold-weather trials were required to validate the data.

The lean-burn combustor has been included in R-R's Advance3 demonstrator engine, the purpose of which is to assess a new and more efficient core for a future-generation turbofan, and of which ground tests began in Derby in November 2017.

The ALECSys development effort is part-funded by the EU's Clean Sky future technology research programme, R-R notes.