This is basically using a generator - motor combination to act as a potentially variable gearbox for the fan, while separating the hot and cold streams from their traditional turbofan coaxial positioning
This could allow more flexibility in managing the cold stream airflow / pressure ratio for better propulsive efficiency across varying flight conditions. But it does bring additional weight, power conversion inefficiencies, and heat rejection complications compared to a 99+% efficient gearbox, and doesn’t solve the core thermal efficiency issues at varying fan power requirements. And the core is still breathing the high temperature inlet air at M3, limiting the power available to drive the fan at those conditions.
Whether the fan adaptability propulsive efficiency gains offset the other cycle inefficiencies will be interesting to see if they can get funding for further development.
