Abstract
Lean burn combustion systems of low-emission modern gas turbine engines admit ∼70–80% of the compressed air through the fuel injector and the remaining air is passed through the liner assembly. The paper focuses on developing an intake geometry to accomplish a 70:30 mass flow split between the injector and liner. A lean burn injector and a liner assembly are developed following the existing design rules and extensive numerical simulations are performed to optimize the combustor assembly. The intake geometry is designed considering different operating parameters such as mass flow split ratio, compressor pressure ratio, liner and injector pressure drop. The pressure drop across the injector is limited as 4% and the liner is optimized for a pressure drop of less than 2% across the annulus of the liner. The diffuser section and intake cowl of the combustor are modified to achieve the required flow velocities through the liner and injector. The topology of the central toroidal recirculation zone and effusion flow velocity field are obtained as per the design requirements. The annular liner passage is modified by providing baffle plates to regulate the mass flow and thereby controlling the mass flow split into the intake section. The intake section is designed such that the required flow split is achieved while keeping the pressure drop and other losses to the minimum. Several geometrical iterations are done until the above goal is achieved. Efforts are currently underway for the experimental validation of the test results.
