TY - JOUR
T1 - Influence of mist droplet injection and blowing ratio on mist/steam showerhead film cooling on a first-stage vane of hydrogen gas turbine
AU - Kong, Dehai
AU - Li, Xinhui
AU - Bi, Ran
AU - Liu, Cunliang
AU - Niu, Xiying
AU - Isaev, S. A.
AU - Terekhov, V. I.
AU - Penyazkov, O. G.
N1 - Publisher Copyright:
© 2025 Elsevier Ltd
PY - 2025/12/1
Y1 - 2025/12/1
N2 - Numerical simulations of mist-assisted showerhead (SH) steam film cooling on the vane's leading-edge region of a hydrogen gas turbine have been performed under elevated operating conditions. Six rows of cylindrical film cooling holes were arranged staggered in a collinear counterflow layout. The steady Reynolds-averaged Navier-Stokes (RANS) approach in combination with the k-ω Shear Stress Transport (SST) turbulence model and a phase-coupling Lagrangian stochastic trajectory model was used to predict the mist/steam two-phase turbulent flow and film cooling performance, as well as the droplet dynamics in a cascade. The effect of mist concentration (ms) and droplet size (dp) with uniform and nonuniform distributions, for a range of blowing ratios (BR) from 0.5 to 2.0, on the mist-assisted steam film cooling effectiveness (FCE) on the showerhead region, pressure side (PS), and suction side (SS) of the vane was examined. Results for air coolant were also presented for comparison. It was found that steam provided higher FCE than air coolant, and the addition of mist could further enhance film coverage. With increasing ms, the FCE significantly increased on the vane PS and SS, especially at high BR, where the maximum FCE enhancement ratio reached approximately 26.2 % and 30.1 % at ms = 15 %, respectively. However, in the SH region, the mist proportion yielded a slight effect, and the best mist/steam FCE was obtained at BR = 0.5, independent of ms due to coolant lift-off. The effect of droplet size on FCE enhancement was closely related to the BR. The highest FCE enhancement ratio at the SH region was approximately 24 % at dp = 10 μm and BR = 2.0 due to mist evaporation. Furthermore, cases with uniform and nonuniform distributions of droplet size exhibited nearly identical film cooling on the vane surface, while significant differences in droplet trajectories were observed, particularly in the SS region.
AB - Numerical simulations of mist-assisted showerhead (SH) steam film cooling on the vane's leading-edge region of a hydrogen gas turbine have been performed under elevated operating conditions. Six rows of cylindrical film cooling holes were arranged staggered in a collinear counterflow layout. The steady Reynolds-averaged Navier-Stokes (RANS) approach in combination with the k-ω Shear Stress Transport (SST) turbulence model and a phase-coupling Lagrangian stochastic trajectory model was used to predict the mist/steam two-phase turbulent flow and film cooling performance, as well as the droplet dynamics in a cascade. The effect of mist concentration (ms) and droplet size (dp) with uniform and nonuniform distributions, for a range of blowing ratios (BR) from 0.5 to 2.0, on the mist-assisted steam film cooling effectiveness (FCE) on the showerhead region, pressure side (PS), and suction side (SS) of the vane was examined. Results for air coolant were also presented for comparison. It was found that steam provided higher FCE than air coolant, and the addition of mist could further enhance film coverage. With increasing ms, the FCE significantly increased on the vane PS and SS, especially at high BR, where the maximum FCE enhancement ratio reached approximately 26.2 % and 30.1 % at ms = 15 %, respectively. However, in the SH region, the mist proportion yielded a slight effect, and the best mist/steam FCE was obtained at BR = 0.5, independent of ms due to coolant lift-off. The effect of droplet size on FCE enhancement was closely related to the BR. The highest FCE enhancement ratio at the SH region was approximately 24 % at dp = 10 μm and BR = 2.0 due to mist evaporation. Furthermore, cases with uniform and nonuniform distributions of droplet size exhibited nearly identical film cooling on the vane surface, while significant differences in droplet trajectories were observed, particularly in the SS region.
KW - Droplet dynamics
KW - Hydrogen gas turbine
KW - Mist injection
KW - Steam film cooling
UR - https://www.scopus.com/pages/publications/105016313791
U2 - 10.1016/j.applthermaleng.2025.128373
DO - 10.1016/j.applthermaleng.2025.128373
M3 - 文章
AN - SCOPUS:105016313791
SN - 1359-4311
VL - 280
JO - Applied Thermal Engineering
JF - Applied Thermal Engineering
M1 - 128373
ER -