Hybrid Turbofan Engine

Turbofan engines are the critical bottle neck of the aircraft designs. Lack of high thrust turbofan engines limit the payload capacity of the planes. Adding more engines is not the ideal solution. I would like to propose a hybrid high bypass turbofan engine especially for high thrust applications. The idea is to generate high thrust using already availably rocket engines and power the turbofan using the exhaust of the turbopumps of the rocket engine.

The design requires compacted rocket engines to be split into sections and modified to be adapted as a high bypass engine. Unlike air breathing turbofan engines, the hybrid engine I propose will consume liquid oxygen instead of relying on ambient air. However, large turbofan section will suck large volumes of air and increase the amount of accelerated exhaust gas. This will increase the ISP of the engine compared to a rocket engine. The turbofan will be driven by the exhaust gas of the rocket turbopumps.

Main drawback of the engine is its reduced fuel efficiency compared to traditional engines. However, designing and manufacturing very high thrust turbofans are prohibitively expensive and complex.

On the other hand, the advantages of the hybrid engine I propose are:

- They rely on already mass-produced high thrust rocket engines.

- They don’t require ambient oxygen to operate. Which increases their service ceiling.

- They can operate with liquified methane. Which is much greener than jet fuels.

If the future of aviation is hydrogen, liquid methane consuming hybrid turbofan engine would be the next step.