Large-eddy simulation for turbine heat transfer

Abstract

Heat transfer in a high-pressure turbine configuration (from an experiment documented in [1-2]) has been analyzed by means of large-eddy simulation. Blair's large-scale rotating rig consists of a first stator, a rotor and an exit stator. Flow and heat transfer in the first stator are assessed for two configurations-with and without the presence of turbulence generating grid. A particular challenge here is that turbulence grid generates fairly high levels of inlet turbulence with turbulence intensity (TU) of about 10% just upstream of leading edge; this in turn moves the transition location upstream in a dramatic fashion. As far as the rotor blade is concerned, the flow and heat transfer is also analyzed experimentally for a range of incidence angles assessing the pressure side heat transfer increase at negative incidence angles. Several challenging aspects relevant to flow in the rotor are also considered - the three-dimensionality of pressure side flow separation at negative incidence, the impact of upstream stator wakes, as well as the role of surface roughness. Copyright © 2013 by United Technologies Corporation.