Numerical aerothermal analysis of an aggressive intermediate turbine duct

In two-spool turbofan engines, an intermediate turbine duct connects the high-pressure and low-pressure turbines. For modern high by-pass ratio engines, these ducts need to be aggressive(i. e. of high area and aspect ratio), not to become excessively large. In the present work the aerothermal behavior of such an aggressive turbine duct is subject to numerical analysis. The predicted flowfield shows satisfactorily agreement with previously reported experimental data. Two different inlet boundary conditions and two different turbulence models were investigated. The results show the limitations of using cireumferentially averaged inlet profiles for aerothermal predictions. Analyzes using different turbulence models show similar flowfields and heat transfer structures. However the predicted heat transfer levels differ significantly locally