Transition mechanisms on High Pressure Turbine Vane midspan sections subject to varying inlet turbulence

Abstract: Heat transfer to the surface of high pressure turbine blades plays an important role in their design. It has been observed that the levels of heat transfer depend strongly on the inlet boundary conditions, specifically the characteristics of the turbulence such as the turbulence intensity or the length scale. To better understand the effects that variations of the inlet turbulence states have on the flow over the blade and consequently the heat transfer, a series of highly resolved large eddy simulations (LES) has been conducted at realistic engine operating conditions. The results are compared to previous experiments and DNS to establish the accuracy of the LES. Then the boundary layer and heat transfer behaviour is investigated in more detail for the different inlet characteristics studied.