In a dual axial-flow or twin spool compressor system, what does the first stage turbine drive?

In a dual axial-flow or twin spool compressor system, the first stage turbine is responsible for driving the N(2) compressor. This setup typically features two separate compressor sections: the low-pressure (N(1)) and high-pressure (N(2)) compressors. The N(2) compressor, which is located downstream of the N(1) compressor, operates at a higher pressure and temperature.

The first stage turbine extracts energy from the high-temperature high-pressure gases exiting the combustion chamber and uses that energy to drive the N(2) compressor. By doing so, it increases the overall efficiency of the engine and ensures that the high-pressure airflow required for combustion is adequately maintained.

The N(1) compressor is driven by a separate turbine stage further down the process, which is why the first stage turbine specifically powers the N(2) compressor. This distinction is crucial in understanding how power is distributed in a dual spool design, as it directly affects the engine's performance characteristics and its ability to maintain a stable and efficient operation across different flight conditions.