In high bypass turbofan engines, what is the thrust ratio produced by the core in relation to the fan?

In high bypass turbofan engines, the thrust ratio produced by the engine core in relation to the fan is typically around 1:4. This means that for every unit of thrust produced by the core (the combustion process), the fan produces approximately four units of thrust. High bypass ratio engines are designed to achieve greater efficiency and improved fuel economy, particularly at subsonic speeds.

The fan, which moves a larger volume of air, generates the majority of the engine's thrust. In contrast, the core, which includes the combustion chamber and turbine, operates at a higher temperature and pressure but contributes less significantly to the overall thrust compared to the fan. The design favors a higher bypass ratio to maximize the mass flow of air being accelerated by the fan rather than relying solely on the core for thrust generation. This configuration is especially advantageous for commercial aviation where fuel efficiency and noise reduction are important.