Ultra-high-lift low-pressure turbine blade boundary layer passive control in different flow conditions

Effects of Reynolds numbers, free stream turbulence intensities (FSTI) and angle of attack on the steady boundary layer development of an ultra-high-lift low-pressure turbine blade were investigated.The three different types of passive separation control devices, which were dimple, cylindrical wire and rectangular trip, were investigated to further improve the blade performance.Numerical simulation results show that:as the Reynolds increases the profile loss decreases;as the FSTI increases, the profile loss decreases, and then increases;as the attack angle increases in the negative direction, the profile loss decreases, and then increases; as the attack angle increase in the positive direction, the profile loss increases rapidly;when the Reynolds number and the FSTI changes, it is found that the dimple can suppress the separation bubble better and when the attack angle changes, it is found that the wire and strip can suppress the separation bubble better.It is also found that the three passive control methods hasten the transition process so the separation is suppressed, but it increases the turbulent wetted area.