Comparison of turbulence modelling on the secondary flow in the linear T106 cascade at high altitude condition

摘要

Proper estimation of loss generation is a key technology jet engine development. Since laminarization occurs at turbine due to low density at high altitude, evaluation of laminar-turbulence transition is essential to achieve high turbine efficiency. This issue likely to occur at cruising altitude, therefore, loss increase due to transition is critical for fuel consumption. Quantitative estimation of laminar-turbulence transition has been one of the most difficult problems for CFD, and this means that proper transition estimation during engine design phase is difficult even now. The secondary flow is also one of the major loss generation sources in cascade flow. Recently, high resolved LES simulation becomes a powerful tool to estimate such a complex flow, however, from the viewpoint of industry, RANS simulation is still a main stream due to relatively low computational cost. In the present study, secondary flow on T106 LPT cascade with laminar-turbulent transition was compared between RANS transition model and LES. The results showed that transition at end wall takes an important role for secondary flow, and secondary flow can be reduced if transition point of end wall is properly controlled.