How is a dual or twin spool compressor system connected to the turbine section?

The dual or twin spool compressor system is designed for optimal performance and efficiency in jet engines. In such a system, the two compressor spools operate at different rotational speeds. This configuration is achieved through the use of two rotor shafts, where one shaft is located inside the other. The inner shaft drives one of the compressor stages, while the outer shaft drives the other, allowing for improved airflow and pressure ratios.

This inner and outer shaft arrangement enables the engine to maintain stable operation across a wider range of conditions. By having separate shafts rotating at varying speeds, the engine can respond more efficiently to changes in power demand without sacrificing performance. Additionally, this design can reduce drag losses and help manage the airflow through the compressor stages, leading to better overall engine efficiency.

The connection through two rotor shafts, one inside the other, is a critical feature that distinguishes twin spool designs from simpler single spool designs, which are less flexible in their operational parameters.