>>12140724I think the idea is this;
1. Incoming hypersonic air is slowed down in the MHD generator, compressing it, but a good chunk of the thermal energy is converted to electrical energy because that's how MHD generators work
2. This colder, compressed air is mixed with fuel and burned, a la ramjet
3. The hot, high pressure exhaust expands through a nozzle, which also has an MHD accelerator in it, and thus the exhaust velocity and thrust are higher
3.5. Since the electricity to power the MDH accelerator comes from the MHD generator that slows and cools the incoming air in the first place, what you're effectively doing is trading a bit of weight and complexity in order to avoid a basically impossible thermal management problem that would otherwise require Skylon-levels of precooler dark arts. For the relatively small amount of heat generated in the MDH coils and the transmission cables you circulate an active cooling loop of fuel, and the same goes for the skin of the leading edges and other points of high heating. Cover every exposed surface in a highly insulating, highly thermally emissive TPS coating of varying thickness and off you go.
