Numerical Simulation Of Combustor Of Wreath Tube Gas Turbine

Wreath tube gas turbines are widely equipped in warships. Combustor is a key part of gas turbine, whose performance is directly linking to its lifespan and power output. Cracks are found on combustor chamber of the wreath tube gas turbine, on its right side and just near the conjunction area of flame tube. The numerical simulation is carried out to study its flow field and combustion performance, to find out the cause of cracks and to supply reference for future advancement design.Due to its complicated structure, 3-D model is created in Pro-E and then meshed in Gambit with unstructured grids. The numerical simulation is based on the SIMPLE algorithm in Fluent. RNGk ?εturbulence model is chosen for reversed flow exits in chamber; the atomizing, heating, vaporizing and boiling of diesel oil are simulated with discrete phase model; The non-adiabatic PDF model andβequation are chosen to simulate combustion.The simulation of cold flow, atomizing and combustion under designed condition are performed, what's more the cause of cracks is predicted. To further research of combustion in chamber, simulations under 5 different excess air coefficients after swirlerαand 5 different angles of swirler bladeαs are executed respectively. The temperature unbalance coefficient of outlet planeδchanges with differentαandαs, which are illustrate by their graphs. Also the temperature graphs of the centerline of chamber under 5 differentαand 5 differentαs are presented.Conclusions are followed. (1) The temperature unbalance coefficient of outlet planeδgoes down as the excess air coefficient after swirlerα goes up; (2) The temperature unbalance coefficient of outlet planeδhas a decline trend as the angle of swirler bladeαs goes up; (3) The bigger the excess air coefficient after swirlerαis, the diesel oil starts to evaporate and finishes combustion earlier in chamber and the temperature distribution of outlet plane is more even; (4) The bigger the angle of swirler bladeαs is, the diesel oil starts to evaporate and finishes combustion earlier in chamber and the temperature distribution of outlet plane is more even; (5) The flame and chamber are not coaxial due to the flow exists in flame tube; (6) The different expanding of chamber in uneven temperature field is one of the main causes of cracks.