Particulate Deposition Patterns on Gas Turbine Vanes with Hot Streaks
Particulate pollutants are highly susceptible to depositing on turbine vanes under high-tempera-ture and high-velocity gas flow conditions,leading to the degradation of turbine aerothermal performance.Hot streaks in the combustion chamber exacerbate the complexity of the flow environment,posing signifi-cant technical challenges for the study of particulate deposition effects.To elucidate the migration patterns and deposition characteristics of particulates in the turbine environment in non-uniform temperature fields,numerical simulations combined with user-defined functions were employed to investigate the effects of turbine inlet hot streaks on particles deposition of the first-stage stator vane of a high-pressure turbine under actual operating conditions of aero engine,by means of applying a Gaussian temperature distribution at the turbine inlet to simulate hot streaks and varying the hot streaks temperature ratio and their relative circumferential positions to the vane.Results show that when the hot streaks are positioned directly in front of the vane leading edge,a large number of high-temperature particles impinge and de-posit on the leading edge surfaces.As the hot streaks are aligned with the vane mid-passage,more high-temperature particles deposit on the mid-chord,back chord and trailing edge regions of the vane,as well as the leading edge of adjacent vanes.Increasing the hot streaks temperature ratio causes the high-tem-perature center of the hot streaks trail to concentrate towards the midspan position,increasing low temper-ature area and reducing overall deposition levels on the vane surface.In contrast to a uniform inlet tem-perature case,the hot streaks not only increase the amount of deposition on the vane surface,but also magnify the deposition differences between adjacent vanes,with the highest deposition efficiency differ-ence reaching up to 11.6％,thus intensifying the inlet flow field non-uniformities towards downstream ro-tors.
gas turbinehot streakstemperature ratiouser-defined functionparticle deposition
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