Aerodynamic performance of a highly-loaded low-pressure turbine profile

Based on Lantry-Menter transition model,aerodynamics of a highly-loaded low-pressure(LP) turbine profile with a Zweifel lift coefficient of 1.2 at different freestream turbulence intensities and Reynolds numbers,both under steady and unsteady inflow conditions,were numerically investigated in this paper.The numerical results show that,the freestream turbulence intensity has remarkable effects on the boundary layer flow on the profile suction surface and the profile loss at low Reynolds numbers under steady inflow conditions.At low Reynolds numbers and low freestream turbulence intensity,the unattached separation flow existing on the suction surface near the trailing edge leads to the rapid increase of the profile loss relative to that at high freestream turbulence intensity.The suppression of the separation bubble by upstream unsteady and periodic wakes can further reduce the profile loss at low Reynolds numbers.It can be concluded that the current LP turbine design system should take into account and make well use of the true environment characteristic of high freestream turbulence intensity in LP turbines.