Effect of splitter location on the characteristics of a vane-type pre-swirl system

The current study proposes a new pre-swirler configuration with a splitter for gas turbines. The pre-swirl vane with low aspect ratio results in strong secondary flows and high endwall loss. The splitter concept is demonstrated to reduce aerodynamic loss and improve swirl ratio. The discharge coefficient and swirl ratio increase after the distance between the vane and the splitter is adjusted. Numerical simulations are conducted to validate the performance of the pre-swirler with a splitter. The total pressure loss at the exit of the pre-swirler is reduced by 14 % to 17 % when the splitter is installed. The exit yaw angle increases when the space between the upper vane and the splitter is reduced. Consequently, the increased exit yaw angle increases the tangential velocity at the exit of the pre-swirler and the swirl ratio of the pre-swirl system. A vane-type pre-swirler with splitter is recommended to improve the performance of the pre-swirl system.