3 ms·

I just saw an interview with more detail and it sounded to me like they were going to have the turbine drive a generator powering an electric motor to drive the

I just saw an interview with more detail and it sounded to me like they were going to have the turbine drive a generator powering an electric motor to drive the fan. Like a diesel electric locomotive. And this is supposed to allow it to transition from turbofan to turbojet to reach mach 2.7 to allow starting up a ramjet which launches the second stage to mach 5 before lighting its rocket engine. Not sure why none of that detail was mentioned here. https://youtu.be/Detvd2EqWWU https://youtu.be/Detvd2EqWWU

JumpCrisscross 3y ago
> the turbine drive a generator powering an electric motor to drive the fan Maybe the transmission losses aren't relevant if you're thrusting for a short interval? > transition from turbofan to turbojet to reach mach 2.7 to allow starting up a ramjet Oh. Cool. Sounds like an air turboramjet [1]. Plus a fan? Not sure how you ditch the fan, nor why they'd describe an electric motor driving the fan as an electric compressor. Granted, I skimmed the video. [1] https://en.wikipedia.org/wiki/Air_turborocket https://en.wikipedia.org/wiki/Air_turborocket
- modeless 3y ago
  The ramjet is on the second stage, separate from the turbofan/jet on the first stage. The loss in the electrical system should be pretty small, and they claim that they gain a lot of efficiency from being able to optimize the engine over the whole range from 0 to mach 2.7.