吹风比变化对篦齿通道流动性能和气膜冷却效果的影响

Installing labyrinth seals on shrouded blade tips effectively reduces leakage losses at the top of the rotor. With the increase in turbine inlet temperatures, it is necessary to employ film cooling technology to ensure the stable operation of shrouded blade tips. This paper employs numerical simulation to investigate the effect of blowing ratio variation on film cooling within a labyrinth seal. All results are obtained at a main passage Reynolds number of 10000. The results indicate that increasing the blowing ratio enhances the sealing characteristics of the labyrinth seal. The film cooling effectiveness at the cavity bottom is determined by the relative strength of the coolant and the recirculation zone. When the coolant momentum is high, the coolant can easily diffuse within the cavity, resulting in higher cooling efficiency. However, when the coolant momentum is low, the coolant is more prone to be entrained by the swirling recirculation, dissipating and leading to lower cooling efficiency.